It's silly that the 3G models don't do voice calls. You could easily do calls using the speaker and, more privately, using a (BT) headset. It's great to be able to use the device while calling instead of holding it to your head like a neanderthal.

I still don't know what the (or my personal) sweet spot for phone size will be. You're trading off essential attributes either way you go. 7" might be an interesting spot if you want to "have" a tablet device and a phone device but don't want to have to own both.

Stashing it is a problem though. I can't imagine lugging it around in my front pockets. Back pockets might work better but are easily stealable and (the bigger issue) you have to sit on your phonetablet all the time. Cargo pants work, but aren't fashionable, and I imagine (from lugging beer^Wwater) that the weight distribution is annoying. Biking clothes have a bigger pocket in the small of your back, and having never worn one, I think that's just about perfect. Or you could do it like Peter Molyneux: http://youtu.be/o6-grRsTupA?t=9m35s