I'm surprised that Skies of Glory hasn't been reviewed here. It's an action packed WWII themed flyer with missions and dogfights. The graphics and audio are some of the best I've experienced on the ipod touch. The bullet/machine gun sounds are so realistic. I think the only drawback is that it starts out as a freemium app. However, yesterday they came out with Skies of Glory - Battle of Britain (6.99) which includes all of the mission packs, plus 4 or 5 additional planes that you can unlock as you pass missions. I'm really getting into the mission aspect of it. The online multiplayer is great too, but don't expect to be very good to start with. There are guys on there with 100,000+ kills. Going through all the missions and unlocking the better planes will give you more of an advantage when you step your foot into the online multiplayer pool.
Are there any other players on the boards here?