If you do not have time to watch the entire Guided Tour for the iPhone 3G S, you can watch short demo videos of just the features you are interested in (that is totally what I did). Below is a list of all the features that have short demo videos and the link to the demo video on Apple’s website. These include features of both the iPhone 3G S itself and the 3.0 firmware.

Video Capturing/Editing – Video Demo
Camera – Video Demo
Voice Control – Video Demo
Compass – Video Demo
Cut, Copy & Paste – Video Demo
Landscape Keyboard – Video Demo
Spotlight Search – Video Demo
Voice Memos – Video Demo