I love bookmarklets! I use them every day (I’m using one right now to post this link). Amber does a great job explaining what they are and how you can make one. I really like the way she frames them as your own personal dev tools!
Drag this to your browser’s bookmark bar now!
Such a useful quick check for resilience—this bookmarklet shows you a side-by-side comparison of a site with JavaScript enabled and disabled.
A handy little bookmarklet for doing some quick accessibility checks.
Have I told you lately how much I love this microformats bookmarklet? Yes? Well, I'm telling you again.