Pros and cons of getting the iPhone 3G S with AT&T?

I need a new phone (I have an upgrade available). I'm not really a big fan of touch screen phones, but it is all AT&T really sells anymore...and if I have to get touch screen, I'd want the iPhone 3G S (since it's cheapest right now). I already have the iPod Touch, so I don't want the phone for music, apps, or internet...so list some pros and cons? Do you like the phone? Not like the phone? Have any other phone suggestions? I want a full keyboard (not the condensed ones like blackberry's), which is one of my only requirements...