Auto-creating empty favicon.ico files sounds like an idea with potential, at least for new sites. We’ll definitely take a look at that. Thanks for the suggestion!

On favicon.gif, people can certainly create one if they want. We show about a 160:1 ratio of favicon.ico 404’s to favicon.gif, so we’re confident our servers can take the heat there. 🙂

Robots.txt, on the other hand, does get hit pretty hard (about 4:1 favicon:robots), but one rogue search engine (at a time) doesn’t create the same access pattern as an Internet mob clamoring for info about the techno-adventures of geek girls. Nothing does, really. 🙂

Judging by some of the comments in the link you provided, blank robots.txt files popping up all over the place can adversely affect people who are dynamically generating them, which makes them sad. So, while people definitely should consider creating one, our servers will just have to continue to tough it out if they don’t. 🙂

Thanks again for stopping by. You’re welcome anytime, especially if you’re bringing good food for thought. Mmm, food… gotta go.