Culturing microworms is pretty easy. Basically you get a shallow plastic container, I use the semi-disposable ziploc plastic boxes, and drill a few holes in the top for air. Then cook some old fasioned oatmeal, let it cool and put it in the container. Sprinkle some yeast on top and mix it in. Then spread the starter culture over the top. In a week or two there will be microworms climbing up the sides of the container. I just wipe some off with my finger and then dip it in the fry tank. You can see hundreds of little worms wriggling in the water as they decend to the bottom. I'm using mine to feed betta fry. Every so often start a new culture in a different container just in case mold takes over one culture. Then rotate the containers as they get old.
There are more complete instructions at clothahumps site:
http://www.eheim-uk.com/micro.asp
Wonderwoman, since you are the first to ask, you can be a test case. Send me a private message with your address and I will pack up and send you some microworms. That way I'll know how much it will cost if someone else wants some.