Poll: What kind of release cycles do you use?

Are your release schedules planned (short-term or long-term), infrequent, a mix, or ad hoc? Let us know by taking this poll.

I've been working on a variety of projects with different release styles lately. Some projects are fairly "catch as catch can," where I do work, test, and release it to production when we are happy. I have one project that is working with a weekly iteration cycle, where we deploy to Production once a week, and patch showstoppers mid-week as needed. I know some people who also use an iterative approach, but their iterations are in months or even quarters. And I have projects operating on more traditional, infrequent, large releases on an "it's done when it's done" basis. What kind of release schedule are you using, and what do you think of it?