Do Not Try This Unless You Know What You Are Doing.
If you don't know what I mean by heap size, do not try this.
Okay, I haven't tried this (yet) my self but a friend of mine changed the heap size in the startup script and managed to slash the memory usage. you might need to tweak the heap size to fit your computer and your computer usage.
You can try this at your own peril, standard disclaimer: Don't bitch to the developers if you break your OneSwarm, your computer explodes, you become infertile and your lover leaves you. You broke it you fix it.