Alter the time it takes for items, weapons, powerups to respawn after being picked up.
Code to be Added or Changed
Just open up g_items.c in the serverside code, right at the top as you open it, you'll notice these:
#define RESPAWN_ARMOR 25
#define RESPAWN_HEALTH 35
#define RESPAWN_AMMO 40
#define RESPAWN_HOLDABLE 60
#define RESPAWN_MEGAHEALTH 35
#define RESPAWN_POWERUP 120
Those are the respawn counters that decide how long it takes before the item will respawn in the map again after it has been picked up. I'm sure you can work out how to change their times. They are counted in seconds.
#define RESPAWN_POWERUP 30
Bringing powerups down to 30, would mean that all powerups reappear every 30 seconds now.