Are All Apple USB cords the same?

Apple USB cords are universal. They work for all their devices despite alterations. For instance, the new USB for 3G has a 1/4 inch plug vs 1/2 but the 30-pin connector remains the same. I've been using a Griffin Powerblock designed for iPods on the iPhone without issues.

Note that car accessories without "Made for iPhone" branded stickers will pull up the Airplane Mode message, but chargers only will not. Most chargers work fine with the 3G but as they get older, they'll stop working. After a few months, you'll have to replace the old ones.

I use the same cords for my iPhone 3G, my old iPhone 2G, my iPod Touch, and my hard drive based iPod. They all with each other with no problems.