I'm working on a project for which I'm the sole QA engineer. We release to production approximately once a week. It's a web app, and a relatively simple one - simple reads and writes. There are probably 30 pages in the app. The only difficult part about it is the release frequency.
Early on, I decided that since I was working alone and releasing often, automation was going to be my friend. So I instituted a rule: no bug gets closed without an automated test written. I made little attempt to automate general functional tests, although I did some as I had the time.
Today, 6 months later, we haven't had a single regression ship. There have been regressions, sure, but they've all been caught by the developers on the project (they have the ability to run the tests I've written). I realize this isn't rocket science, but chalk me up as a fan of this technique!