Looks like everyone is building interesting stuff for use on the web. Via Danny Ayers, I found out that the New York Times has built (and released openly) a database front end they call DBSlayer. It talks via JSON, does connection pooling - it looks fairly interesting. All you need to talk to it is HTTP and JSON libraries. I've made fun of JSON before, but perhaps I let my cynicism get out in front of me.
Update: Looks like there's a Squeak package for JSON - if it works, a port to Cincom Smalltalk should be fairly easy.