Just saw a stop-motion video by Keshen8 that’s not to be missed – it runs like a highlight reel for BrickArms weaponry (though I think I spot at least a couple of Brickforge pieces in there as well – am I wrong?).
I try to update the links every now and then with new custom-weapons shops that catch my eye, but I really only get a tiny fraction of what’s out there, and there are a couple of sites that are much more dedicated and do a much better job.
Most of the customs news I follow these days comes from the Ugly Duckling at Bricklink minifig news blog and the FireStar Toys reseller site. These will give you a much better idea of the full range of minifig options available, and I figure this is as good an excuse as any to pass along some links.