What brand of lenses can i use for my Olympus E-500 DSLR?

I'm having a hard time to find olympus lenses for my camera here in the philippines. Can i use sigma/canon/nikon/tamron lenses? If yes, do i need something before i can use it (ex.adaptor)? I'm confused about the whole micro 4/3 thing and i don't know what it does.

Take a look at http://myolympus.org/E500/
There's a lenses link: http://myolympus.org/E500/
From that it looks like Sigma do produce lenses for your camera.

There's an on-line Olympus users group which may be able to help more. See here

Sima and Tamron MIGHT make lenses to fit your camera - nobody else does.

Specify Olympus mount.

You can use Olympus 4/3 lenses, and Sigma lenses for the 4/3 mount. Your camera is NOT a micro4/3 mount, and you can't use those lenses.

You can use some other mounts via an adapter, Nikon F being the most popular. Canon lenses won't work. An adapter that allows the Nikon lenses to work properly costs quite a bit, the cheap ones only allow the lens to mount to the camera but do not actually connect the electronics. You have to do everything manually, and many Nikon lenses don't have aperture rings. Without the electrocic control, you can't change the aperture on those lenses at all. You can also adapt the older Olympus OM lenses to the 4/3 mount.