Turbocharge your iPhone camera: Four great photo apps

Remember Photosynth, Microsoft's swooshy-zoomy 3D photo browser? If you liked that -- and who wouldn't? -- you'll love Seadragon, which allows you to browse huge numbers of images and even use Photosynth itself.

There's only one thing we like better than stunning photo applications, and that's free stunning photo applications. Seadragon is gratis from the iTunes Store.

But I don't own any black polo-necks, let alone an iPhone! Ask yourself if your mind has been blown today. Then check out Photosynth. Warning: may blow your mind.