while Hipstamatic seems to be quite "in" with its vintage-look photo editing, i really love to play around with WordFoto and am surprised that i haven't seen it mentioned very often yet.
it's a cool, well designed iPhone app with which you can transfer your photos to pictures drawn of words. you can buy it in the iTunes-store for 1.59€, the preview pictures convinced me in an instant.
you can choose from some pre-set designs or also create your own looks, and of course your own captions. i love to play around with it!
this is a really nice app for the money and i think totally worth it. some pictures i would even like to print on a huge canvas to hang it onto my wall - in fact, i should really do that!
you should choose photos with clear, not so detailed colour/intensity elements. additionally, i have adjusted contrast, saturation, definition and sharpness with iPhoto after i have imported them from the phone to make the pictures even brighter and more defined.
but no more talk, you best see a little gallery of my results ;)