Easy Hadoop via Ensemble
People are talking a lot about Hadoop and Big Data. This is an area where a tool like Ensemble can really help out. Juan Negron has distilled the installation process for Hadoop on Ubuntu into a formula.
There is work going on to make the formulas easier to find and share, right now you pull it from a bzr branch, but the project is moving along at a fast rate, you can find out more about Ensemble on cloud.ubuntu.com.