Taking a selfie while driving is obviously as stupid and distracting as texting, but it may not be illegal. Take Vermont, for example. The state has banned since 2010 "the reading or the manual composing or sending of electronic communications, including text messages, instant messages, or e-mails, using a portable electronic device."
Nothing in that law says anything about taking a selfie. "That doesn’t sound like we’d be able to bring a charge just based on someone taking a selfie because we’d have to prove that they actually sent it to somebody,” a former prosecutor told NPR.
Twelve states have laws that ban handheld cellphone use while driving, and that would seemingly cover selfies. In states without those laws someone could be prosecuted for negligent operation for taking a selfie, but there doesn't seem to be precedent yet. Until then Twitter is full people pushing the limit. Just search for #drivingselfie.