I once spent about nine months creating a largish program, and then moved on to another job. I spent about a day educating the fellow who would be carrying on the maintenance. I barely knew him.
About a year later, we met again. I still didn't know him, but he sure felt that he knew me. I remember he greeted me with, "I love your sense of humor", and "If you really want to know someone, you should work on their code for a year." No doubt he knew me as a programmer much better than I know myself.
Code reviews are a great way to get feedback on your work. Like open-source, knowing your code will be seen by co-workers is a strong personal incentive to produce better work.
If your work does not do reviews now, you can still ask a co-worker to look over you code changes. Many people would be flattered that you would ask for their programming wisdom. ;)
