Ideone.com : Online IDE & Debugging Tool. You can run C#, Clojure, COBOL, Common Lisp, and +more (here, via @ajlopez) -- It's both a way to share code snippets and also an IDE. Pretty cool indeed!
Just gone public with a little open-sourcery - Couverjure, a Cocoa bridge for Clojure (here, via @MarkAllerton) -- "I had this crazy idea that Clojure might play nicer with Cocoa than Java did, and wanted to see if I was right." According to the author, the code is still in "proof-of-concept" stage. Still, if you want to see how it looks today, here is a snippet.
new #enclojure is out with #clojure 1.1 support and #netbeans 6.8. Works great so far! (here, via @prpatel) -- Netbeans has become a very fast and usable multi-language IDE lately. Enclojure is a very well rounded plugin for Netbeans to work with Clojure code. Their REPL support is quite unique and smart. You will need to grab the file at the top of the downloads page (named "enclojure-plugin-2010-jan.nbm")
Just finished hacking GridFS support into Clojure's MongoDB driver (here, via @sanityinc) -- GridFS adds support for very large objects into MongoDB. The clojure driver for MongoDB (congomongo) keeps getting more and more functionality.