Here are two tips courtesy of :
12 iPhone Tricks You Might Not Have Known : iSmashPhone
The first tip I found very helpful is when entering a domain suffix you can hold down the .com button and it will bring up .net, .edu, etc...
The second tip I found very cool is that you can take a screenshot of your phone if you hold down the home button and then click the sleep/wake button. The photo will then appear in your gallery.
thanks
drew henson