I actually use OptionHouse. Their customer support are very helpful but I don't use any of their tools. I think their time is 3 days for the funds to clear. You can't keep trading daily either unless you are on a margin account. You have to wait 3 days for your money to go back into "stock buying power" after you sell your stock when you buy it the same day. So quick trades are out of the question. I don't know if this is how all brokers work, optionhouse is my first broker.
When I signed up they had a promo if you funded your account with at least $3,000 you got 100 free trades.
I also get to do my trades at $2.95 since I signed up before they raised to price to $3.95 a trade.
Edit: Actually I used their virtual stock trading program which gives you $5,000 fake money to play with buying stocks for the first few months before putting real money into it. It was a good way to find out if the stock market was my think. After getting my account to $8,000 fake dollars, I figured I'd toss real money into it :)