Then, hold it up by the wheel so you can steer with one or both hands. Also, doing that means looking back and forth from the road is easier.
Or don't text at all while driving. *gasp*
Me, I'll take a call while driving but I refuse to text. And that's just because calling someone is just the same as talking to someone in the passenger's seat (which I do often), but even then I keep whatever conversation I'm having brief.
Cell Phones + Driving = Bad.