I was considering it at one point, but then decided that it wasnt my job, nor the job of the development staff. So it got kicked up to QC and User Acceptance.
There are some pricey automated test suite tools out there, but boy they are expensive, and since I consider my time to be money, it would cost less to buy the tools vs. me actually writing reusable automated UI tests.
Sure, we do code reviews, spot checking, and buddy testing, but once its v1.0 is approved, its out of our hands untill there is a bug or change order. In which case the process repeats.