totally unrelated, but kinda.
i just switched providers today from AT&T to WalMart's new Family Mobile plan (it rolled out 2 days ago). they're using T-Mobile's network. i only use my cell phone for talk and text, and the Family Mobile is only $45/month for unlimited voice and text. that's right: unlimited. got to keep my same phone, same phone number. it's not a contract deal either. *cartwheels*
each additional line is $25/month.
they offer data/web packages, but didn't really look into it since it wasn't something i needed.