i found this on camstuf iden link page

Originally Posted by phonescoop
If you put a Nextel SIM card inside a Boost Mobile,the display will show Enter Special Code, and your phone is temporarily useless.
If this happens, turn off your phone. Put the Boost Mobile SIM card back in the phone. Turn the phone on and let it sit for 15-20 minutes. The display will change from Wait ... to Enter Special Code ______. Turn the phone off one more time, and turn it right back on. Your phone should boot normally.

Ask the tech support department. I'm going to say no initally though, even if you can, the minute you make that sim card switch you null and void your manufactor's warrenty too.

i thought i read somewhere that you can't put a boost sim into a nextel, unless its unlock nextel, but you can put a nextel sim into a boost mobile and it will work. but i'd like to know too?

I think the boost would need to be unlocked..

I have an i870 that is hosed. Im leaving the country within the next 6 months and dont want to buy a mega expensive phone just to leave it behind soon.

can I put my sim card into a boost mobile? I am looking at the cheapest alternative here, so nothing fancy. I dont use the walkie talkie or anything. just to get my email/IM's and texts.

thanks!