If you haven't used MarketCaster on Etrade before, open your portfolio view (any one of them if you have watch lists) and you'll see a tab for streaming quotes. You used to have to sign off on some CYA real-time data waiver, but just takes a minute.

It's a nice real time self-updating view and it's customizable. It's also very easy to add or remove stocks from the board if it's a watch list. If it's the portfolio for one of your accounts it only shows stocks you actually own, but it's easy to set up with a blank or watch list group.