Southbridge heatsink.

I'm sure there is an easier way to get this, but if you have a dead officeconnect cable modem lying around, there is a heatsink on a chip inside that is the perfect size for a southbridge sink (Very low-sitting, and about 0.2mm sticking out on any side of the southbridge. I put one on my board and it gets pretty warm. With a little airflow directed at it, I got my FSB back up to 230 from 223 (lost it with a bios update awhile back)

or you can get any old school mobo
and take off the northbridge hs (its a low profile heatsink with some sticky stuff on it)
and stick it on your sb

Once I get around to it, I'll be upgrading my mobo's (Gigabyte GA-7VAXP) NB heatsink with the blue fanless Zalman, and putting the NB HS on the Southbridge.

is the zalman blue one better or the gold one? newegg sells the gold one for like a buck more but the blue one is newer.

The blue one should be better - it's the same material and same x-y dimensions, just taller. The gold one might be more expensive because it comes with thermal adhesive; the blue heatsink requires mounting holes (or provide your own adhesive), and can't be used on a board with integrated video.

I also used the stock active heatsink from my mobo and put it on the sb. Works like a charm. Although lapping was needed.