Yeah. I do that with my daughter. She has 250 TXT on her line I don't have any. So she and I can communicate that way. I email her phone ([email protected]) and she TXTs my email address.
Ted from Kik. We actually has an app that does just that, to US and Canadian phone numbers.
Check it out: m.kik.com. You get 50 free outgoing per month, and unlimited incoming, but right now you can just click credits in settings and get 150 for free
If you have any thoughts, would love to hear them - ted at kik dot com