Only one that I know of is Global Forex Trading http://www.gftforex.com/ Not saying there are not any more, but thats only one I know of..their software is actually pretty damn nice. Includes a full API too. My only grief with them is when I applied to open an account it took fricking ages for them to get back to me so I ended up with someone else.
any others?, trailing stop is an important feature, I am sure other traders were looking for this as well
Cybertrader has trailing alerts and can be based on bid, ask, or trade price. In order not to get jerked out of a trade by a bad tick, I always use bid and trade price for long stops and ask and trade price for short stops.
Yup - GFT does offer this although only in their new release version 2.0 of DealbookFX - this is still in beta phase although I believe they are preparing to move across certain live customers. Cheers