The are a number of texting apps you can download. Also if you've upgraded to iOS5, it has iMessage. That allows you to text to any iOS device (iPhone & iPad).
I enjoy it. It has remarkable batter life, even when I'm jamming on the synthesizer apps (SampleWiz and MorphWiz). It has more entertainment value for me than it does utility. I know other people who use theirs for work and a glorified PDA and are happy with it.