I've changed the slides enough that I wanted to be sure everyone who wanted them could get the latest version. I normally go for a lightweight, zen-esque approach in my slides, so that unless you come to the talk, you can't just read the slides and get the good stuff. But if you've heard the talk, the slides make great sense.
For this talk, I went the other way... everything is in the slides... I'll try to do an HTML export of them if anyone wants one, but here's the Power Point file.
Use C to Tune Your Rails Application
It's very much an introductory talk, so if you're looking for advanced content, I'd suggest you go straight to the Older, free version of the Pickaxe book, buy the Pickaxe, second edition, and visit How to Profile Your Rails Application and Make Rails Go Vroom!.