Safari Development Tools
It seems like all the cool development tools are for Firefox these days. Anyone who has tried to develop for Safari knows the pain of debugging due to lack of good development tools. It appears that this is just about to change.
My buddy Keith hit me up with a link to Xyle Scope, a Safari add-on that gives you unconditional access to any page’s CSS and HTML information. You can edit CSS code on the fly and see your changes applied instantly, as well as take a trip through the source code to see how a page is layed out. Hopefully this is just the beginning of good development tools for Safari!