Ah, I hadn't sifted through the API...I was just looking at Twitter's own search widget configurator, which includes a checkbox for Safe Search.
On another front, should the feed refresh periodically? I see you say something about every two minutes, but I still have the same set of tweets rotating after an hour. Changing the SSL option doesn't seem to matter. (I'm using it to search for tweets on a topic, rather than display my own tweets—and I'd love for it to just keep pulling in new messages.)
Thanks,
Doug