The motorola Atrix had demos of this concept. There was no ubuntu- it just was moto's skinning of android & a $200 docking station for your phone/keyboard/monitor.
I'm sure the other carriers are out there doing similar things.
Twilio's api solves a pretty interesting set of problems, but the 180 billion dollar market cap for AT&T is not based on the problems Twilio is working on.
It wasn't particularly successful.