Third time’s a charm? HP tries yet again to crack the netbook market, and its third endeavor is its best entry yet.

Using the Mini 2133 as a base design (complete with anodized aluminum case, bezel-free LCD, and spacious keyboard), the Mini 2140 has upped the flagship netbook’s screen size to 10.2 inches (though HP claims it 10.1), which lets the keyboard grow to 92 percent of full size. Vista has been ditched in favor of XP, and HP also adds a couple of netbook rarities here, including an SD slot and an ExpressCard port for your WWAN card (or whatever else that port is ever used for). There’s even an accelerometer which parks the hard drive if a drop is underway, and the keyboard is spillproof.

Some nifty add-ons, yes, but ultimately the 2140 looks and feels awfully familiar, not just in design but also in under the hood specs from the CPU (1.6GHz Atom) to the RAM (1GB) to the hard drive (160GB), components which are quickly becoming standard in the netbook space. Performance is average, too though the 2140 wouldn’t run Quake at our usual benchmark resolution.

The good news: The 2140 is distinguished in one way, and that’s battery life. The standard three-cell battery (which gives it a weight of 2.6 pounds, in line with the competition), coupled with LED backlighting on the screen, gives the 2140 a running time of 2 hours, 27 minutes, which is longer than other 10.2-inch netbooks by at least 15 percent. A six-cell battery is also available, which should keep you up and running for a solid 5 hours.

But there’s a dark side, too, and that’s price. Of course, it just wouldn’t be an HP netbook if it wasn’t expensive, and though at $499 it’s the cheapest netbook at launch from HP to date, it’s still wildly more costly than the competition. Lenovo, for example, is now selling its similarly equipped IdeaPad S10 for just $399. That said, if you think you might spill $100 worth of coffee on your mini-note, the extra cash might be worth it.