I had just returned to my desk after eating my lunch and a decently sized spider came walking along in front of me on the desk.  Panicked I threw the chair backwards, jumped up shrieking, and probably let out an expletive.  I did grab a napkin and tried to squish it as it climbed up onto my computer, but when I moved the paper there was nothing to be found.

I leave it to you to decide if I was seeing things or if I rightfully spent the afternoon freaked out that there was a spider silently stalking me from a crevice in my cube.