Patchwork
overview
PatchWork is a web-based patch tracking system designed to facilitate the contribution and management of contributions to an open-source project.
Patches that have been sent to a mailing list are 'caught' by the system, and appear on a web page. Any comments posted that reference the patch are appended to the patch page too.
The project's maintainer can then scan through the list of patches, marking each with a certain state, such as Accepted, Rejected or Under Review. Old patches can be sent to the archive or deleted.
current setup
If you'd like to check it out, Patchwork is being used on the Linux PPC64 Development list. Have a browse here