Measuring Coder Performance?

An Anonymous Coward asks: "Our company is a small web development firm that focuses on dynamic and database-driven websites. We are thinking about creating a bonus/recognition program for our coders based on their performance. The question is, how exactly does one measure programmer performance? We don't want to use the number of lines of code per day (why encourage 10 lines when 5 will do?). We don't want to use the time it took to finish the project, since lack of bugs, speed, security, etc. is just as important as time. Has anyone had an experience with a measurement system that they thought was a fair and accurate measure of the quality and speed of coding?" While I'm sure some standard can be applied to answer this question, I don't see it being extremely accurate. Some things just can't be quantified. I'd be interested in knowing if you all think this is one of them.