Linux normally does not use swap at all. It only swaps out dirty pages that are not referenced anymore for any reasons. Use 'free' to see the actual swap usage, for example. But! Swap is still a part of virtual memory, and does need to be present in the system that is RAM-hungry. For example java apps, that allocated virtual memory for heap. Just run top and see that in most cases virtual memory allocated to a process exceeds physical RAM used by this process. So in the absence of swap, a new application might not be able to start due to not being able to reserve enough virtual memory even if there is enough RAM for it to run, or a system out-of-memory daemon will go kill some consumers of ram and this that can be pretty bad! See also description of vm.overcommit sysctl option which IIRc should be set to 2 for best results, provided that there is plenty of virtual memory.
to conserve disk space used by the swap partition, you could perhaps make for it a special LVM volume that is thin-provisioned, i.e. that takes less physical space on disk than it presents to the system. You'll only need to allocated some megabytes worth of disk space and the system will see whatever gigabytes of swap partition you like. Please excuse for not giving you full details, they tend to leave my head with little traces
, but do check out man page for lvcreate or may be some other man pages related to LVM. Do post back your findings