Quest Visual has created an app called Word Lens for the iPhone, available on iTunes. It translates printed text on the fly between spanish and english. Incredible, totally justified my iPhone.
There's an introductory video on Youtube, where someone picks up posters with Spanish on them, and the app translates the Spanish words to English right there. It's a little hard to believe, because it keeps nearly the same fonts and colors and stuff, but it's still awesome. The language packs are $5.00, but compare that to Rosetta Stone, and do the math.
It actually works - which must have been pure hell to write. Kudos to Quest Visual!
No sign of it in Android market, more proof that Android is what you buy when you can't handle having an iPhone.