Switch between full-screen windows of the same application in Lion

You can switch between spaces using ctrl + left right arrow keys, but this can be used with all spaces not just Xcode

I can switch between windows of the same program by dragging four fingers left or right across the trackpad. This is analogous to pressing [Command] + [~] when the windows are not in fullscreen.

You can find this setting under System Preferences>Trackpad>More Gestures.

This is not the perfect solution as its a paid one, but this software called Which fills this gap. As this is truly a bothersome problem (I often use five or six RDP connections at one time in full screen) I thought I would mention it.

disclaimer : I am not affiliated to this program.