The version of Safari used by the iPod touch is ostensibly the same as the version used by the iPhone, but carries a slightly different user agent string.
- iPod Touch user agent string Mozila/5.0 (iPod; U; CPU like Mac OS X; en) AppleWebKit/420.1 (KHTML, like Geckto) Version/3.0 Mobile/3A101a Safari/419.3
- iPhone user agent string Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420 (KHTML, like Gecko) Version/3.0 Mobile/1C28 Safari/419.3
Notice the different in device identifier, and the different build number.
Unfortunately, this means that the iPod touch will not, currently, navigate immediately to the iPhone-optimized versions to which many sites automatically redirect -- a temporary problem until site authors adjust for the change.