Akinator

Self-proclaimed "Web Genius" Akinator is a fun little browser-based app which expands on those twenty question games we all know. Akinator is shockingly good at identifying characters, and frequently gets even the obscure ones; he got Dani Filth, Jim Raynor and Napolean without any trouble.

Swingify

Swingify is a little browser based app which puts almost any song into a swing tempo. For some reason, this is great fun, especially if you pick something with a good bassline. Crazy Train works frighteningly well...

Cyanide & Happiness

If you've seriously never heard of this comic, get over there now; you can find a link for it here, but prepare to lose a few hours of your life if you've never seen it before...