http://www.radioshack.com/product/i...ease&kw=grease&parentPage=search

Ian,
As unhappy as I am of what Radio Shack has become over the years, most should still carry this. I think you can enter your zip and check avail. Allied, Mouser, Digi-Key, Newark(inone), MCM(inone) are all online sources. Of course you have to decide if you need thermal joint compound or a thermal bonding compound.
Joe