there are different providers of level 2 - I use ADVFn, but other members use another provider, and feel it is far superior.
One thing I like about ADVFN is that it know includes the time of every order, as well as highlighting all those placed in the last few minutes in a different colour. Useful to see rapid changes in buying-selling pressure.
Another useful tool discovered tonight are "heat maps" at www.nasdaq.com.
Using colours again, and passing a cursor over an equity gives a small intraday graph, stats etc.
The bad news is that on the Nasdaq 100, most were down. And most of these closed at they lowest price of the day...