In online trading, you can see the rates at which a scrip can be sold or purchased (just like vegetable in vegetable market). even with a difference of Rs.0.05, u can buy and sell. whereas if u buy thro' a broker, you have to quote the rate and wait for the order to mature. So you can open an account with someone like Sharekhan, etc., use their software and order online. Only constraint is during trade hours, u shd be in a position to order. That is, if u r working somewhere, during 9.00 to 15.45 hours, u may not be in a position to trade online