I posted at getsatisfaction.org in the latter stages of the Stanza crisis. there are a number of links which used to be in the stanza catalog, which is now defunct thanks to amazon killing the lexcycle website.
http://getsatisfaction.com/stanza/to...ered_in_stanza
They should be useful generally but IIRC there are a couple which are web pages rather than OPDS catalogs (munseys comes to mind immediately)