Buying most cellphones takes minutes, but getting one of the must-have new smartphone handsets is an endeavor that could last weeks.

Apple iPhone 4, which sold out of pre-orders for its June 24 launch, currently has a three-week wait through the company and AT&T. The HTC Droid Incredible, launched in April on Verizon Wireless network, ships within a month of ordering, and Sprint Evo 4G (another HTC phone) is backordered indefinitely the company s site isn t taking orders, and refers customers to check back later.

We generally always have phones available for our customers, says Brenda Boyd Raney, a spokeswoman for Verizon, who calls the backorder of the Droid Incredible an anomaly. AT&T did not respond to requests for comment. Sprint did not respond, but passed the request to manufacturer HTC. Both Droid Incredible and Evo handsets are shipping regularly, but a wait for parts has bottlenecked supply, says HTC spokesman Keith Nowak. We re going as fast as we can at this point, he says.

Consumer frustration over handset availability is actually helpful for carriers, however, says Michael Hodel, a stock analyst covering the industry for Morningstar. Demand builds buzz, which may entice more customers. As long as people eventually get their phones, the short-term annoyance of a wait causes minimal problems, he says.

Here s how to minimize the wait and maximize savings:

Steer clear of the secondary market

Sellers on eBay and Craigslist are well aware of the demand for popular handsets, and jack up their prices accordingly. (One 16GB iPhone 4 recently sold for $820, a 312% markup over its $199 price tag at Apple.com.) If you don t want to pay a lot more than retail, you have to wait, says Alex Goldfayn, a consumer electronics expert who hosts the nationally syndicated radio show The Technology Tailor Minute.

Willing to pay the premium? Browse completed auctions to determine the average selling price. That way, you can spot the bargains.

Trade in the old model

Shoppers who are content to wait for a retailer to get stock may be able to wrangle store credit on the spot from trading in an older handset. For example, a 16GB iPhone 3G in good condition could fetch $77 at Best Buy, or $100 at RadioShack, both of which offer in-store trade-in programs. RadioShack will consider most phones in working condition, while Best Buy limits its program to devices purchased at the chain.

Weigh the wait

Before you sign up for a month-long wait, check to see if the carrier has newer handsets due out that might be a better fit, Hodel says. Verizon, for example, has offered to let buyers of the Droid Incredible make a penalty-free switch to the Droid X from Motorola, due out July 15. Review service options, too. You re making a sizable commitment, with a two-year contract for phone service, he says. You might as well get the phone you really want to use.

Check retailer inventory

Wal-Mart, Best Buy and other electronics retailers let consumers check online for store availability. (According to BestBuy.com s records, a store in Manahawkin, N.J., had the elusive Evo in stock Tuesday.) Call the store to confirm availability. Staffers may be willing to set aside the phone if you re able to come by soon after.

Get on wait lists

Many individual stores generate wait lists of consumers hunting for a specific phone, Goldfarb says. So long as you re not handing over a credit-card number (which would make it a pre-order instead of a wait list), there s no harm in putting your name on several.