FrostyTech posted a review on the Xigmatek MAC-S3501 DDR/DDR2 Memory Heatspreaders

Xigmatek's MAC-S3501 memory heatspreaders are intended for DDR and DDR2 memory modules, and assuming the sticks of memory you have are bare, installation is a quick affair. A thin strip of jelly silicon thermal interface is laid down on the DRAM, and then the anodized aluminum Xigmatek MAC-S3501 heatspreaders are set in place. If on the other hand your memory already has heatspreaders that are attached with adhesive or frag tape, there's a good chance you may destroy your memory if you attempt to remove the heatspreaders.

Xigmatek MAC-S3501 DDR/DDR2 Memory Heatspreaders Review