Open Source Code Reviews?

Wordman asks: "The Slashdot article on making software suck less got me wondering about how open source projects make use of the (by far) best tool for reducing software suckage: peer code reviews. Normally, a project team is assigned a fellow programmer's code to look over and critique; however, with open source projects, the 'team' is not as cohesive and usually scattered geographically. Additionally, most open source projects do not have a 'project manager' the way a company would. So, what experiences have you had with code reviews in an open source project? What was the process? Did it work? If it didn't, what went wrong? How would you go about starting a code review process in an open source project?"