This page demonstrates some of the Web Services calls in the jQuery Library for SharePoint Web Services.
As of the v0.5.3 release of SPServices, you should not be prompted for credentials, but if you are, use these:
Username: demouser
Password: demouser
(As in "Demo User" -- nothing to do with rodents.)
Use the links below to see the results of some of the Web Services operations we've currently got implemented. The library is under continual development, so leave a comment in the Codeplex Discussions if you'd like to see something which isn't available.