Some people claim that because the iPhone doesn't support Flash, you can't get the full Internet on it. But with these apps--all of which claim to bring Flash to the iPhone--that's no longer true. The question, of course, isn't whether they can play Flash, but whether they can play it well enough to make it usable. That's a different story.
Photon (US$3.99) offers the best Flash playback of all the apps on this list. It achieves this by connecting your iPhone to a remote computer running Flash and then streams its desktop to you. Flash is solid: you'll see some pixelation, but over Wi-Fi, it's acceptable for occasional viewing (3G is a bit worse). Photon can access Hulu or online game sites like Kongregate. Some of its other features are a bit weak, but it's your best bet for Flash. Overall rating: 3.5 stars out of 5.
Another app that streams a remote desktop session to your iPhone, CloudBrowse ($2.99) seems aimed at corporate users. That's because not only does that app cost $2.99, it has a $9.99/month subscription attached to it. CloudBrowse is surprisingly fast, but its Flash playback is spotty. Video is jerky and audio gets out of sync quickly--plus, Hulu blocks the browser. A good attempt, but probably not the right choice for the average user. Overall rating: 2.5 stars out of 5.
Puffin ($0.99) is the other app on this list that's able to bypass Hulu's blocking of the iPhone. However, once it does, the quality of its Flash playback simply isn't that good. Video looks more like a series of still images than a smooth movie. It's speedy, though, and offers a solid array of other features, so it could be a real contender if its Flash features are shored up. Overall rating: 2.0 stars out of 5.
SkyFire ($2.99) is an interesting case. Rather than trying to actually play Flash movies on your iPhone, when you try to load one, SkyFire's servers take over and automatically convert the Flash file to an iPhone-compatible version and then stream it down to you. It's a relatively young app, and in its early days its servers got overloaded by the heavy-duty video conversion, so we don't have a final grade yet. If it works, though, it could be the best option for bringing Flash to the iPhone. Overall rating: Incomplete.