You d never know Jessica Harbin was among the ranks of unemployed recent college grads by the way she s been jetting around lately. In the past year and a half, the 24-year-old from Novi, Mich., has attended shows on Broadway and toured the monuments and museums of Washington, D.C.; when winter s chill set in, she even jaunted to Jamaica for some tropical beach therapy. Next up on her jam-packed vacation schedule? A dream trip to the Costa Rican rainforest.

It s all a far cry from her usual dirt-cheap travel mode of red-eye flights and crashing on friends couches. But that s because Harbin is tapping a tried-and-true source to underwrite her trips: the bank of Mom and Dad.

Hey, boomers! Don t look now, but that lump in your hotel room s other bed is a relative traveling on your dime. With the anemic job market taking a bite out of discretionary income, young adults who might prefer getting rowdy with friends in South Beach find their only getaway option is playing Scrabble with the rents in a rented vacation condo. And folks who once financed expensive family outings with home-equity cash are now packing their progeny (and sometimes themselves) off for an all-expenses-paid trip with Nana and Pop-Pop. The travel industry calls such trips multigenerational or intergenerational vacations. According to Virtuoso, an international network of luxury-travel advisers, consumer interest in such trips has tripled in the past two years, making it one of the industry s fastest-growing segments. And travel providers say they re seeing more elders covering all or most of the tab. Indeed, for many grown children struggling in the downturn but still wanting to leave town not having to foot the bill is the bottom line, says Nancy Nelson-Duac, owner of Texas-based Generations Touring Co.

It s no surprise, of course, that the beleaguered vacation industry is fostering family togetherness. Cruise lines, long the go-to option for family reunions, frequently offer discount rates on the second, third and fourth cabins a party reserves, while hotels have begun courting extended families with deals like grandparents-stay-free packages (Jamaica s Franklyn D. Resort) and activities like cooking and flower-arranging classes (Four Seasons Costa Rica). In recent years tour providers have put an intergenerational spin on everything from white-water rafting to do-gooder volunteering. And fallout from the financial meltdown has only boosted the appeal of such bonding. In times of distress, says Peter Yesawich, chairman of travel marketing and research firm Y Partnership, people turn to family for solace.

But given the complexity of family dynamics, solace is rarely the only emotion in play especially when not everyone is paying equal freight. Trip beneficiaries may wonder if they re obliged to shuffle along with Mom through yet another museum when all they really want to do is hit the sports bar. (Oh, the guilt!) One 20-something grad student whose parents treated her to a Vegas jaunt expressed shock when her father suggested they attend a topless revue. (Her response: No way! No matter how classy. ) There s logistical awkwardness: On Harbin s travels, she never felt hungry at 5 p.m., her folks preferred dinner hour. And then there was the mortifying moment when, during a scuba excursion, someone mistook her dad for her spouse. Harbin emerged from the water hyperventilating and sputtering, He s. Not. My. Husband. He s. My. Father.

To be sure, it s not all wince-worthy. Traveling with loved ones can forge strong bonds. Grandparents often report that travel gives them uninhibited time with their grandchildren they rarely get when the middle generation is running interference. When Marilyn Oswald, a New York City family therapist, and her husband, Peter, take their grandkids to Europe, she says, pleasant surprises abound from their 9-year-old grandson s discovery of Goya at the Prado in Madrid (they d been prepared to leave the museum after 10 minutes) to his older sister s big-time bonding with her grand-p re over French cheeses. Jim Moses, president of Boston-based Elderhostel, which offers more than 200 grandtravel itineraries, says the organization often gets posttrip letters from kids saying, in essence, I never knew my grandma was so cool.

Even 20-somethings do more than just tolerate the situation. Shari Newman calls her annual Colorado ski trip with her parents dreamlike. And no wonder: The 27-year-old marketing professional from New York City says she doesn t touch her wallet all weekend ( It s like a savings plan! ); she gets quality time alone with the folks, without the ordeal of coordinating with her two siblings families; and she enjoys a steady diet of fine food and wine. For Newman it s a Peter Pan experience: I can be an adult and a kid all at once.

Indeed, for recipients, such gift trips are a sweet deal. After all, transportation, lodging and meals add up fast on any kind of vacation. From a money standpoint, the least fraught option is the grandparent-grandkid trip, since it s frequently a birthday or graduation gift. But with other arrangements, resentment can build quickly whether one cousin chooses a hotel beyond the price range of others or siblings pay on a sliding scale for expenses, leaving parents to help the less flush. Penny Lemov, a Washington, D.C., writer and editor who blogs about parenting grown children, has planned 20 years worth of trips with her own and says it has taken almost that long for her kids to transition from being completely treated to paying at least some of their share. She calls it the Daddy indulgence curve.

If money matters don t kill your vacation buzz, there s always the challenge of pleasing family members of differing ages, abilities and interests. Tour companies are often proactive about assessing whether Grandma will be able to, say, get in and out of the kayak. But many itinerary planners engage in wishful thinking (of course those 11-year-olds will sit quietly through an academic lecture with Dad!) or fail to set common-sense limits on who can come in the first place. (One Himalayan family trek offers to carry children under 50 pounds in specially designed porter baskets. ) Other companies have intergenerational programs that largely segregate kids and adults activity-wise, bringing them together primarily for meals.

But tour providers say they re learning what works. Martin Rapp, a multigenerational expert with international travel agency Altour, says adventure tours, in particular, keep families active together. Hands down, he says, the most popular are those that bring travelers up close with wildlife: safaris, Alaskan cruises, Gal pagos trips. One luxury safari company, Micato, which says family groups represent 35 percent of its business (up from just 10 percent in 2001), gets grown-ups and kids to interact in activities like fireside trivia contests and volunteer projects at schools and orphanages.

For those who travel independently with adult kids, travel expert Nelson-Duac often recommends cities like Edinburgh that have abundant public transportation, culture and nightlife, along with apartment rentals, so folks can come and go more readily than they could with a shared hotel room. Lemov has her own solution to three-generation getaways: serial vacations. She rents a condo or villa for two weeks, one week for each of her grown children s families, with overlap in the middle. That way, she and her husband aren t going crazy navigating different budgets and nap times: You can pay attention to them individually.

For Tiffany Joyce, a supply-chain specialist from Chandler, Ariz., a crucial component of a successful family vacation is getting the money part right which involves treating adult kids like, well, adults. In fact, she postponed a planned Hawaii trip this summer because the kids, both in their early 20s, hadn t saved enough to cover their share of the costs. While she and her husband are offering airfare and accommodations, the kids need to pay for meals out, entertainment and an additional rental car. I remember the first time my stepson pulled out his wallet and said, I ve got this, says Joyce. It was surreal.