Sadly, I searched high and low for this stuff, and I couldn\'t find it by the spool. I found some silver chain about 18\" long in a craft store for making jewlery but it gets kind of expensive.
But I found an incredibly cheap solution! A grocery store near me has a gumball machine that has crappy toy necklaces for 50 cents! They are pure shit, but the chain is really tiny and about 18\", so I get several uses out of each. I buy one every time I go food shopping so I got lots of back up.
You guys should always check those stupid machines, I find they are very useful for bits. There are two at K-Mart that I hit-up all the time, one with DC heroes and one with Scooby Doo figures. Both are in the 30-35mm scale, perfect for cutting up and using for basing and what not.