I am looking for one from ebay, and some covers say for 2g/3g/3gs. Since ebay is not such a trusty side, I was just wondering how I can find out if the cases promoting will fit my phone too.
Nope, the iPhone 3G and 3GS are thicker than the original iPhone 2G. Also the 3G and 3GS back is curved out so those covers won't fit into the 2G correctly.