As somebody with a smartphone, I'll give you all a great tip. Silent mode. Put it in your jacket/backpack/purse/manly-burlap-sack.
My phone is ONLY on loud when I'm on-call or during work hours when I'm out of the office. I only check emails during office hours, or when I'm on-call.
Otherwise I check my phone every once in a while for missed calls/texts. If its important most people will call more than once/send a text/send an email, and I call back, otherwise I just leave it.
All the usefulness/convenience of a smartphone (in certain situations), with none of the "chained to work/the system" that people seem to think comes with it. And if your boss rags on your ass that you didn't answer your phone at 10pm when he tried to call you, thats his problem, not yours. If your woman/friends nag at you, have them send you a text or leave a voicemail. *gasp*
btw: Nokia E71 is the best smartphone without any useless bullshit hanged on it, like Steve Job scrotum. And it gets excellent battery life.