Finding Good WebBase Brokers

I would like to know if there is any good
web base broker so I can start a demo
account.

I prefer something that is webbased because
I am not stuck on only one computer and
I can practice when I am out or at work.
I wonder if there is any limitation regarding
webbased broker opposed to software.

Simple answer - Oanda, great broker, poorish charting, runs on Java