Can you have any phone with boost mobile? Or just a selected few?

Supposedly, you are restricted to Boost phones, although I have heard of short-term success using an old Nextel phone with a Boost SIM card. Boost claims they can shut off a Nextel phone on a Boost card, however. It will not work with GSM phones, Nextel used IDEN instead.

With Boost, any Nextel or Boost phone will work. It's that simple. If, however, you want to use your phone address book and such, you need the right SIM...the oooold 32k ones for two-digit model number phones and the new 64k SIMs for the three-digit phones. There are now absolutely enormous (for SIM cards) 128k SIMs, but I'm not sure whether they are even on Boost...maybe Nextel-only. But yeah, any Nextel phone will work on Boost...forever...

Thanks for the clarification, iansltx. Please remember, though, that the Boost and Nextel phones will not work with GSM SIM cards such as the ones from Cingular or T-Mo -- even though they may fit in the slot.

Yeah, hence my omission of GSM phones from the picture. Heck, you can't even use some iDEN phones on Boost (SouthernLINC comes to mind).