Does anyone know the minimum deposit on the major online stock trading sites?

I really would like to invest and i wouldnt mind looking for diamonds in the rough and that sort of thing, i dont have a ton of money (being that i am a student and really would like to start small and eventually go big with some stock investing), i am aware of the commission fees of most of the companies, but i know there are minimum deposits on some (such as td ameritrade is about 2 grand, and scott trade is 5,000 or something like that, but ive heard everything) but if someone could clarify all of this for me and tell me the minimum deposits for the online trading sites like etrade, scotttrade, td ameritrade, and other sites that other may not know about. Thanks.