...a friend at work just told me about
SitterCity.com. Within about 15 min of reviewing the site, I registered for an annual membership. Usually I discuss things like this with Michael first, but Michael's out of town for 3 weeks this month. So I guess I'm rather motivated already.
I already have 2 reference checks out via email and I have 2 more that I'd like to call tomorrow.
Sounds promising!
Edited 10 min later: OMG, I got a reply already!