OMG - yes. My T (T, then ex-T, now part-time sort of T while I look for someone else) usually has his phone on, with the ringer off, sitting right next to him.

The problem is - he gets messages on it. Or maybe it's visual notifications of incoming calls? Either way, he sees them - they get his attention while we're talking. And he stops to check out who's calling or what the message is. Having your T distracted by his phone is a really terrible feeling, talk about feeling unimportant and like you don't matter.

It's a big enough thing that when I had a session where he didn't have the phone, once, I walked out feeling better... and it took me a second... but I realized that it was b/c he wasn't constantly checking his phone.

Therapists out there - and therapists-to-be - please, please have your phone off and out of view when you're in session!