A great phone that gets ahead of itself.
+ Many Cool Apps (for free)
+ Decent Keyboard
+ Glass Screen (very scratch resistant)
+ Good Camera
- Terrible Battery Life
- Slide mechanism feels flimsy
- Phone freezes a lot
- Not very stylish
- Terrible Speaker
I'll keep this simple, the G1 is a great phone. The Android Market is awesome, and there are many free games and apps that will keep you entertained for a long time. But that's about the only good thing I can say about this phone. If you try and navigate through menus too fast or have too many widgets on the screen, the phone will slow down to a crawl. Sometime it will take 10-15 seconds to load the home screen. Also the physical design of the phone is terrible, when you slide open the phone the top half feels flimsy and loose. It's not very sturdy. Also, the battery life is TERRIBLE. You will be charging this phone every day, even if you don't use it much. There's also a long delay when you take pictures.
In closing, the Android OS is very good, but this phone can't run it very well, it just doesn't feel powerful enough. And the design needs work.