You are also able to get Sky Mobile TV on Vodafone, Orange, T-Mobile and 3 - go to Sky by Mobile for further info.
I've got it on Vodafone, bargain for ?6 per month.
Experienced jailbreakers probably wouldn't buy it I guess, however inexperienced people would quite likely pay 1.99 if they're convinced the information contained within can answer all of their queries. Would save trawling the net for answers.
Good luck with it if you decide to take it on :)
I use the iPod part of the iPhone loads, still use my iPod Classic 120GB a fair bit though as that holds all of my music whereas my iPhone only has my preferred tunes.