Unlocked Palm Centro goes on sale for $299

Now you can grab the compact smartphone without a contract, although you'll have to pay a $200 premium for the privilege.

On sale now at Palm's Web site, the $299 unlocked Centro will work on any GSM network—which, here in the U.S., means either AT&T or T-Mobile. All you need is a working SIM card.

You can already get a Centro (see my hands-on impressions) for $99 through AT&T, Sprint, or Verizon Wireless, but of course, you must sign a two-year contract to get the bargain price.

And consider this: Just a couple of years ago, I paid $399 for a Treo 700p—an older, clunkier version of the Centro—on Sprint, and that was with a two-year service plan. So yeah ... $299 for a pretty solid unlocked smartphone isn't that bad.

Now, a couple of things about the unlocked Centro: only a GSM version is available, so it won't work on CDMA carriers like Sprint and Verizon Wireless.

Also, the unlocked Centro is EDGE-only, which means you won't be able to tap into AT&T's HSDPA network (or T-Mobile's upcoming 3G network, for that matter) for speedy Web browsing or streaming video. (Both Sprint and Verizon offer 3G EV-DO versions of the Centro.)

And finally, make sure to check with the carrier/operator of your SIM card before you start checking e-mail or surfing the Web. (The Centro lacks Wi-Fi, so you'll have to get your data over EDGE or GPRS.)

Unless your SIM has a flat data plan attached, you could end up paying by the kilobyte—and that could lead to an unpleasant surprise when your bill comes.