N.D.
I also heard of sitter city, but some of the sitters turned down offers at the last second. I agree there always seem to be so many moms in my area, but they keep to themselves. Wherever I go. Even at my daughter's Gymboree class they just are not willing to mix much.To this day I still haven't found a mom's club in my area.
I also have used www.helpersabove.com for finding babysitters and nannies. My friends and I have used them and they are really good.
I found my babysitter through word of mouth but heard these two places, including Craig's List, are good places to start. Also try posting ads at the local college campus. Good luck and start early!