I'm with AT&T... I got my iPP on the 13th from . I haven't activated my iPad for cellular use just yet. But today.. I was just curious to check under T-Mobile. They have that 5GB 5 months plan for 10 bucks.
I decided to go ahead and try it out. If I had activated my iPad under AT&T.. I'll be paying 50 bucks in the span of 5 months, granted I could perhaps use more than 5 GBs in that span using my own AT&T plan. But 10 bucks for 5 GB... It's not bad at all.
Isn't AT&T also $10/mo to add a tablet to an existing mobile share?