How about map/gamemode voting?
Any map that is on the server can be voted if you haven't disabled the map voting in the configs.
You can change the gamemode too if your config allows it. Taken from example (ktx.cfg) config on suomicom:
// free modes
set k_defmode 4on4 // default mode on server
set k_free_mode 5 // who can issue XonX/ffa/ctf commands (0 = noone, 1 = admins, 2 = elected admins, 3 = judges, 4 = elected judges, 5 = all)
set k_allowed_free_modes 15 // allowed free modes (bit mask):
// 1=1on1, 2=2on2, 4=3on3, 8=4on4, 16=10on10, 32=ffa 64=ctf
k_allowed_free_modes = 15 => 1on1/2on2/3on3/4on4 = 1+2+4+8 = 15