What's a good, used model of phone for AT&T? Just to be used for voice and texting, no internet. I'm not interested in 'upgrading' to a smart phone, so I figure to pick something up on CL or elsewhere. I have an old clamshell that I've had for about 12 years (yes it still works), but I'd like something a little handier for sending texts, something with a QWERTY keypad. Suggestions?