I found this handy-dandy needle conversion chart at
http://www.yarnfwd.com/main/needleconv.html
Depending on where you live, you could find it helpful when talking on our forum or others - most of the people are in the U.S., and talk about 2's & 3's, 8's & 9's etc. I'm Canadian and we use metric, so - totally different. You'd think I'd get used to it and remember on my own...apparently not, lol.