The iPod touch doesn't come with the soi-disant unlimited Wi-Fi offered for the iPhone in the UK and Germany (see "iPhone Launch Set for UK and Germany, with Murky Data Plan," 2007-09-20); there's no Wi-Fi at all included in the United States. But O2's UK partner The Cloud, a network of nearly 8,000 hotspots across Britain, has created a special £3.99 ($8.07) per month pricing plan for iPod touch users.
The service starts on 01-Oct-07, and has no minimum commitment. There's a special sign-up page. The Cloud's deal differs from the free access for iPod touch users at Starbucks coffee shops in the United States. With Starbucks, access is free only for use of the iTunes Wi-Fi Music Store; with The Cloud, the paid deal covers all Internet usage.
Given how little Internet bandwidth an iPod touch would reasonably use outside of music purchases, I'm a little stunned Apple hasn't cut deals with hotspot chains for unlimited free Wi-Fi access for iPhone and iPod touch users in exchange for a cut of the revenue from music purchases.