Some of you may have played various RTS games. You may recall that all RTS games contain upgrades/research for new/better equipment. Since Tremulous is a fusion of FPS and RTS, how about when stages increase, you can go to the defense computer, open a menu, and select an upgrade to research? So instead of instantly gaining the ability to buy Pulse Rifles/helmets/etc, you have to research it first?
The aim of this suggestion is to increase the usage of defense computers. Most teams past stage 2 don't even build the defense computer, and I think it's a little unused.
Aliens could have their alternative by opening the upgrade menu through the booster.