Time to revive this thread.
I've got two ideas, both could be used independently or in combination.
1. Having arrows at the egde of the screen indicating the other players' positions. In CTF and TDM modes the arrows are blue and red (the flag's arrow could be shown with a black border, a circle inside or something similar), in DM the colors are equal to the Tee's body color. The transparency of the arrow depends on the distance between the local player and the target. Targets far away would be shown with an arrow of little opacity. Nearby targets have an arrow of higher opacity.
Click to see the example:
http://img411.imageshack.us/img411/3164 … 052es7.png
2. When in spectator mode you can move the camera freely with the mouse. There should be the same function when playing. If you hold down a button you can move the camera through the map and locate flags/enemies. When releasing the button the view is centered back on the local player. This could be especially useful when spawning to get a quick overview.