Hmm that's a tough one. in XP the standard taskbar is 30 pixels. The sys tray is just a few pixels less.
There is also a class that you can call to obtain such details, Shell_TrayWnd. Although, I've never used it and wouldn't know where to begin. Sorry.
-Geates
"I hope I can feel and see the change - stop the bleed inside a feel again. Cut the chain of lies you've been feeding my veins; I've got nothing to say to you!"
-Infected Mushroom
"I do not offer answers, only considerations."
- Geates's Disclaimer