You can purchase a phone/sim off ebay and start prepaid service -- or
from a local T-MO, Target or other store that carries such starter kits.
 If you have NO reception at your home and you don't mind, that is
fine.  When you travel, if you have reception in the area, the phone
will work.

I live in area code 804 and have T-MO service.  I bought a sim card off
ebay and gave it to my son.  It has an 818 area code for North
Hollywood, CA.  He thinks that is cool.  That phone works here, of
course.  I also converted an 804 number prepaid to a 414 number and gave
it to my mother in Milwaukee, WI.

Best,

Stan

Sure. You'll find that prepaid Sidekick II's are hard to come by even in
popular T-Mobile areas. You'll probably find them only at T-Mobile corporate
stores for $329 less $50 rebate. You can get one for $30-$60 less via web
retailers like Amazon. If you don't need it until summer, you might as well
wait to see if the Sidekick III is out by then.