Though we've long known that there's value in stocks flying beneath the radar, Tom Gardner's notion of hidden gems investing is really taking off these days at The Motley Fool. So, too, is tiny overnight air-cargo outfit Air T (NASDAQ:AIRT), which might be a tad diminutive even for Tom G's taste.

Small or not, it's hard to argue with success. Thursday, after the close, tiny Air T reported a 31% jump in fiscal year 2004 revenue. Net income fared even better, leaping from $0.13 to $0.80 a share. The stock even offers a 2.6% dividend.

And for all that -- not to mention a few days of frantic trading -- the stock trades at around 10 times those trailing earnings. How unloved is that!

A few caveats: Air T not only operates in the shadow of FedEx (NYSE:FDX) but under its wing. The company is free to seek business anywhere, but FedEx accounts for more than two-thirds of its revenue. And Air T leases almost all of its aircraft from FedEx. It's a cozy relationship that needs to be carefully watched by investors.

At the same time, a unique operating model spares Air T the operating expenses that have occasionally crippled airlines like American (NYSE:AMR) and Delta (NYSE:DAL). That's because the airline's cost of fuel, flight crews, landing fees, outside maintenance, parts, and certain other direct operating costs are billed to the customer at cost.

Believe it or not, Air T is one of the largest "small-aircraft air-cargo operators." But, when it comes to stocks, it is a Lilliputian. With only 2.7 million shares outstanding and a market cap of less than $30 million, it is a true micro cap.

And no, Air T does not enjoy the operating margins of giant United Parcel (NYSE:UPS). Then again, it doesn't trade at 27 times earnings, either. It does, however, boast more cash than debt, rapidly growing earnings, and a dividend.

For now, it's high-risk -- a flyer, perhaps? In other words, watch it, but be careful. Both today and friday, the stock has outpaced even good-news winners Taser (NASDAQ:TASR) and business software upstart Actuate (NASDAQ:ACTU), which landed a nice plug in Barron's.

Bottom line: You might want to let things cool down, but this little number might yet grow into a true gem.

With its light trading volume and tiny market cap, Air T wouldn't cut it as a true Hidden Gems recommendation. It could turn up in the newsletter services' "Tiny Gems" feature, new this month. Click here for a free trial and to see what all the fuss is about.

Fool contributor W.D. Crotty does not own any of the stocks mentioned.