I am trying to customise a TableView in my iPhone application. I have found many tutorials that do this but they are all for version 3.0+. I want to make my application as generic as possible so I can get it to work on as many iPhones/iTouches as possible.
Is it possible to create a customised TableView for 2.2.1 to 3? I've found nothing and am beginning to think that it's not possible.
You can customize the table in 2.2.1 AFAIK. In fact the tutorial you linked to above was written months before iPhone 3.0 was released!
But I have to agree with the comments above, supporting anything below 3.0 is probably not worth it. In particular, pre-3.0 you would initialize a UITableViewCell using initWithFrame, a method now deprecated. So if you decide to support 2.2.1 you risk your app not working on future releases of iPhone OS. With 4.0 around the corner this would not be a wise move.