There is a $10 T-Mobile prepaid Blackberry plan for data. Perhaps you could apply that to the N900 the same way people have applied the T-Mobile Sidekick plan to the N900.

That leads me to ask whether or not it is possible to use the BB plan on the N900, if so, has anyone tried it?

BB plan (last one):

http://www.t-mobile.com/shop/plans/prepaid-plans.aspx

Check this thread for more info on T-Mobile prepaid (some people were even able to use the $10 dumb phone data plan on the N900:

http://talk.maemo.org/showthread.php...hlight=prepaid