A flash hard drive specialist, an air-rescue operator and a California maker of $250 blue jeans are among small companies whose shares are up more than 50% this year.

On the whole, large-company stocks are doing slightly better than small-company ones at the moment. Through Monday, the Russell 1000 index, whose components have an average stock market value of $62 billion, is up 5.7% this year. The Russell 2000, with an average market value of less than $900 million, is up 4.4%.

A handful of small companies have paid off spectacularly, though. A smaller handful still look reasonably priced.

Clothing seller True Religion (TRLG) is up more than 80% this year. Since July 2008, when this column recommended the stock, it s down 12% -- about half the broad market s drop. That s surprising. America s economy since that time has suffered a sudden plunge in consumer spending and a shift in preference from pricey stores to discounters. Yet the Vernon, Calif., maker of $250 jeans is faring well. On May 5 it reported a 19% increase in first-quarter sales and a 10% improvement in profits. Shares can be had for 14 times forecast 2009 earnings.

Cal Dive (DVR), a marine construction company serving oil and gas drillers, is making good money from hurricane repairs and international expansion. Earlier this year it was expected to struggle with a decline in new construction on slumping oil prices, but with crude recently rebounding to a seven-month high, Cal Dive shares are up more than 50% for the year. They re still priced cautiously at 11 times earnings.

Few companies are growing like Santa Ana, Calif.-based Stec (STEC) right now. Its first-quarter sales increased 25% vs. a year earlier. The company makes solid state drives, which do the job of hard disks with no moving parts. They re still expensive for personal computers, although no longer ridiculously so. Dell charges $325 to swap the 500-gigabyte hard disk on one of its high-end notebooks for a solid state drive, albeit one-half the size. Companies that use heaps of servers have already started paying up for solid state, though, perhaps because the drives use less power and serve data faster. Stec s Zeus drives are the industry performance leader at the moment, and sales of the drives more than tripled last quarter. Management says it should hold its performance edge at least until next year. Good thing: Even after assuming earnings per share jump to 85 cents this year from 31 cents last year as expected, the stock goes for an ambitious 20 times earnings.

Air Methods (AIRM) stock is up 20% since I recommended it in August 2006, vs. a decline of more than 25% for the broad market. The company operates air ambulances, flying the gravely ill or injured to or between hospitals. It can operate under contract with hospitals, providing only pilots and aircraft for a largely fixed fee. It can also serve communities, providing flights, medical workers, billing and everything else and collecting fees based on flight volume. The latter type of deal carries a little more risk, but much more reward. The company s average yearly sales per hospital base are about $1.2 million with a profit margin (before taxes and interest) of 3.9%, according to Avondale Partners, an investment bank. For community bases, average sales are $2.9 million with a 13.6% margin. This summer, Air Methods expects to convert three hospital bases to community bases. Earnings per share this year are expected to jump 42%. Shares still seem reasonably priced at less than 13 times forward earnings.

Below are listed details on these and two other small companies with big recent price gains.