Also known as webspeak, chatspeak is basically an illiterate way of typing, and a way to massacre a language. Shortening words (such as you to u), insisting on ignoring captials, making words numbers, (such as 2 or 4) and not using endmarks are all parts of chatspeak. For most people it annoys them shitless, but certain people insist.
Dis is a ex of chatspek 4 u lol. i cant speel 4 mi lyf n im on aim 247. go figur.