I know a bunch of people have mentioned in their journals how they wish there was some way to add a small amount of weight to dumbbells, so you don't have to make the jump from, say, 50 lb dbs to 55's. I just thought I'd post a link to a company that offers light, magnetic plates:

http://www.theplatemate.com/

They are called platemates - there are three kinds, the hex version and the donut version look like the best bet.

Hope that helps someone...