Palm's website is now offering unlocked GSM Centro smartphones for $299. The picture shows a white Centro with gray number keys, rather than the green that AT&T's version sports.
Quoting Palm's email:
The Palm Centro smartphone gives you voice, chat-style messaging, email and web, along with a color touchscreen and even a full keyboard. (So you can say L8R to those tricky keys on your cell phone.) All of this in a phone that's a whole lot smaller than you think. And now Centro is available unlocked for the flexibility you want. It's also GSM ready for happy traveling.
An unlocked phone lets you pick your carrier, so you're not locked into a contract - though the carrier might insist on contracts, just because they can. You do not need to pick a carrier on the buy page if you choose the unlocked version. Palm's also offering free shipping, a big $5.97 benefit.
An unlocked phone won't work without a carrier, but it will behave just fine as a personal digital assistant. Hook it up when you're ready.