you might try Review Board: http://www.review-board.org/ which was developed by a couple of the coders at VMWare. It's now in use by several big and small companies, from Cisco and Motorola to Twitter and Meebo.

EDIT: Also, supports subversion and git.

I'm not a big fan of Review Board for the following reasons:

- It's not effective for large changes because it presents all the diffs on a single page

- It makes it difficult to jump around in the code. I prefer being able to open the code in my editor of choice and jump around in the file using ctags or whatever code-navigation solution you use

- I would like better code-navigation features

It's not a bad tool, but my team didn't find it very well-suited to its needs

I looked at review board yesterday, and didn't really like how well it integrated. It seemed like there was a lot of manual patch creation. I'd prefer something that monitors the repository, automatically creates reviews, and sends them out to a group of people.

I can get close with Crucible, I'm currently looking into that a bit more.

something like this?: http://code.google.com/p/rietveld/

I think rietvald only works with Subversion (I'd want Subversion and git, at a minimum), and it relies on Google App Engine.

When I first heard of rietveld, it only worked with Perforce but I see it now works with subversion.

If you want something that works with Git, you can use gerrit from google. They are using this for Google Android code inspections.

Smart Bear Software's also used by Cisco