[CAT/Rigging] How to ensure your rigging has perfect symmetry?

First off, sorry if this has already been covered and solved before, I did a brief search on anything pertaining to symmetry in CAT system rigging/skinning, but couldn't find anything relevant!

I'm starting to get into the "meaty bits" of skinning one of my characters (something I've been holding off for WAY too long!), and before I get too far down the line, I just wanted to ask if there was a technique or tool anybody knew of which allowed you to basically "mirror" the weight setup of a rig to both sides of the model? For example, theres quite a lot of fine tuning going on in the hands and feet of my rig (on a per-vertex level), and having to transpose all of those little tweaks, one by one, to the opposite side of the model would just take forever and a century, and I'd also probably end up missing, or forgetting some verts or their precise weights somewhere down the line, which would probably lead to big problems in the animation stage.

Does anybody know if theres anything available within Max 2011 or CAT which allows you to do this? It would save SOOOO much time!

Thanks in advance!