[bwooceli]

you can use their normal programmable wireless for that. I did and pay $1/month to have a sim sit in a $30 Nokia dumbphone that the kids can use when they ride their bikes to the park.

There are ... quirks. Turns out the SIM cards have a "real" phone number that you don't know about, so even though you're routing calls and SMS through your twilio number and outbound dials only show as the twilio number, you will still get random calls that don't hit the twilio network. My sim's "real" number is a detroit number, and I used to get a handful of collections calls on it from the previous occupant of that number.