Just finished giving a presentation on the Rules module in Drupal 7 for ASU Dev Day. Great audience, great venue (Skysong!), and my first time visiting Tempe, despite working for ASU for a few years now. Funny how things work these days, telecommuting and all.
Rules is a definite shining star in Drupal 7. Wish there was video for the presentation that I could share, but alas.
A coworker recently clued me in on Webgrind, a platform independent, browser-based PHP profiling application. I was impressed with it, and thought I'd contribute to the installation and usage instructions that are floating around the web with my specific setup.
Assumes you're using MAMP on OS X, but you can probably adapt.