It's pretty much one of the coolest gadgets ever. It is a phone, an ipod,an internet browser (which shows the real internet, rather than the crappy one that other cellphones show) and can be much more through downloading apps through the app store, with a selection of 20.000-30.000 apps. It has a great UI, which even the dumbest of people can master. It runs iPhone OS. The iPod Touch
runs the iPhone OS too. Three versions of have existed:
a. iPhone Edge 4GB, 8GB
b. iPhone 3G 8GB, 16GB
c. iPhone 3GS 16GB, 32GB
The biggest difference between those models is their speed. The original iPhone has slow internet. The 3G model has higher internet speeds and the 3GS generally runs faster. The iPhone 3G and 3GS have almost the same mass and weight (3GS weighs 2 grams more). Some people say that it sucks, but most f them haven't even touched one and they say it either because someone told them, they hate apple or are jealous.