Is it possible to buy a Boost Mobile phone and take the SIM card out and put it in a Nextel BlackBerry, would I be able to use the web broswer and email? What would be the charges? (minutes, data fees, etc.)?

has anybody tried this?
also what is the best (past or current) Nextel BlackBerry. I want a speakerphone, too. i know some of the older BBs didnt have a speakerphone.