RDF Converter: Convert all that good data into standard RDF.

Collaborative filtering library: Write a library to make collaborative filtering easier.

Regression GUI: Write a GUI to let people who don't have degrees in statistics do neat things like regressions on their data.

Forget RDF and GUIs: Share clean code examples of real-world dataset wrangling.

Web As Corpus: Participate in a Web as Corpus workshop or evaluation: (http://webascorpus.sourceforge.net/)