How to make limited use command blocks

Question

on my 1.5.2 server i would like to make a 1 time use command block so everyone on my server can use it once can anyone help me please (it will be used in 1.6 to give everyone 2 horses)

Answer 1

This will remove just the command block from a certain player in a radius you want. I think you can put an xyz coordinate instead of player or radius too, haven't tried it though. Hope this helps a bit :D

/clear @p{r=10] minecraft:command_block