When i re-updated my system i set my swap at 500 MB. I have 256 in ram and have never even gone into the 250 mb of swap that i had originally configured. How do I reduce the swap?

What OS are you running, that is very important to the answer.

Is this just UNIX box for personal use? Do you need that 250MB back for something else?

Depending on what OS you are running, you can remove swap by editing the /etc/fstab file. I would just comment it out and leave it there if you change you mind in the future. If this new swap area is separate from the orginal 250MB and then reboot.

If not, like in HPUX, there should be an Admin tool that will allow you to manage the swap and reduce or add it. Some systems you must go into single user mode to alter swap and then reboot.

No matter what you do it will require you to reboot when you are done.

Although it is only recommended, most major UNIXs like HP, AIX, Compaq recommend strongly that you have double your memory in swap. This is including root swap and secondary swap.

RH 7.2

I went to to fstab and removed one of the 2 swap entries, but it did not reclaim the once used MB.

Redhat (and other linux variants) use a seperate swap partition. You'd have to fdisk those partitions as linux native, then mke2fs the partition.
Unless your disk is really small, however, it'd be safer, less of a pain, and probably a good idea to just keep the swap there, and keep using it (even if you rarely do).