And then I thought--wouldn't this be a neat thing to do to a fic? It's a good way to see if you're overusing any words you shouldn't be, but it's also a fascinating insight into the structure of your story.
You can run a huge amount of text through TagCrowd at once: I cut and pasted 140,000 words in and it didn't have a problem. Here's some of my results (with possible spoilers):
From NUMB3RS fic:
And from SPN fic:
So I guess if I had to identify an overused filler word, it would be "around" or "away" or "going". Sheesh. I also appear to be obsessed with eyes and voices and other body parts, but you can't really blame me given the material I'm working with, can you?
Any other observations? Want to make your own and post a link? The stories I used are all over 25K words, but I'm sure smaller ones would work, too.