The RegRipper is an open-source application for extracting, correlating, and displaying specific information from Registry hive files from the Windows NT (2000, XP, 2003, Vista) family of operating systems.
Harlan Carvey has written a number of extremely useful tools, and his blog is an extremely useful resource. e.g.
It is also worth noting that regripper has its own dedicated forum. Additionally regripper can be harnessed together with Moyix's tool to parse registry information from Volatility.