I put a cap on this morning (raining outside... must keep bald head dry...), and took it off once I got to the truck. No sooner had I taken my cap off than a wolf spider hopped out. I'm not panicky about spiders, but I would have rather not had one sitting on my head.

I was immediately reminded of my inability to recognize a brown recluse, so I did a little research just now to confirm that what was on my head this morning was not dangerous (it wasn't). Here's a good info page on wolf spiders.

This page shows two good pictures of a brown recluse, with some tips on how to identify one.