How can I switch my cell phone?

I want to get a cell phone different then the one I have now. I have AT%26amp;T service provider. What is the cell phone that is made for texting? I forgot the name... also what type of cell phones are nice... under $100.00, and is it an easy process to change phones?How can I switch my cell phone?
A good phone for texting would be BlackBerry Curve 8310 . The phone has lots of positive reviews on it. It is a good phone for texting too. How can I switch my cell phone?
Att blackberry curve is nice.

I've had it for about six months.

It's a little slow for texting but it's great other for that.

Make sure you get a memory card for it so you can have pictures, videos, etc.

One bad thing is that my version of the curve doesn't take videos, idk about the newest version.

It's abut $100.

Not hard to change either.How can I switch my cell phone?
The best place I have found to buy a phone without a contract is: http://www.myphonedied.com