Apple released a new iPhone 3GS recently and although I have bought every new iPhone on the release date, this time around they didn’t allow for me to get the updated pricing until 12/12/09.
The newest iPhone adds a few features that the older 3G doesn’t have.
Few of the new features include video recording, voice control, better 3MP camera with tap to focus, built in compass, and a faster processor.
Since I didn’t upgrade and have had my current iPhone for over 1 year, I decided to Jailbreak my 3.0 firmware using RedSnow.
After Jailbreaking my iPhone I now have Video recording and a few features that I really like.  For example I can now tell if I have received mail without unlocking the phone.  Also I was able to add five icons to the bottom dock.  Stuff like that really makes using the phone much better in my opinion.
I have yet to decide if I want to get the 3GS when December 12th rolls around since they probably will release another version next summer.
Apple promised MMS with 3.0 firmware update, but they haven’t rolled it out and now they announced it will be ready September 25th.  2 years late, but better late than never.
More iPhone information can be found here - http://www.apple.com/iphone/