Well just got an IM from a friend of mine that bought a $400 palm based PDA phone, only to find out the phone is severly crippled. A phone that has a Palm OS, should have no problem doing 2-way SMS text and MMS. But as you read the review of this phone online, (which seems to be a good site), you see many features lacking.

Mobiledia review of the i500

Some people on the internet have filed the void, and created some applications that allow this core cell phone technology to work again.

Text Messenger 2.1.0

BTW, anyone with a Palm based Cell Phone might want to look at SnapperMail, a very good POP3 mail client. Of course, Palm just switched to PocketPC. or should i say "Windows Mobile", and so all these functions will work by default, but it doesn't run any PALM applications. So you have to switch to a windows interface on your phone, which I can't say I like.