The newest version of Google Goggles has some nice upgrades - barcode scanning is faster, and it'll recognise and search print ads for you. But really, the hands-down coolest feature is automatic Sudoku solving. No need to use your brain!
While it sort of (actually, completely) defeats the purpose of Sudoku to begin with, it's definitely a hell of an impressive demo. Google sent one of its software engineers to beat the pants off of Tammy McLeod - 2009 national Sudoku champ - with his Google Goggles 1.3-equipped Nexus S. Watch the look of masked agony on her face as she realises she's been defeated in her life's passion by a piece of plastic. Puny human! [Google]