I use an iPhone when I'm out and about which I normally hold in in my right palm whilst tweeting, texting, mumsnetting etc etc, my work also involves a lot of mouse work using my right hand. I have been using my phone a lot more lately as my laptop is working really slow and I've noticed tenderness in my right shoulder and armpit and achiness in my right arm - I'm going to give the phone a rest for a bit but wondered if anyone else gets this?