If you have a scroll wheel mouse, you can use OmniWeb to 'hover scroll' background windows. Try this experiment.

Open two OmniWeb windows that require vertical scrolling, and position them so that you can see a fair bit of the back one. Move the mouse over the back window, and use your scroll wheel without clicking in the window to activate it. It scrolls! Move the mouse over the front window, and you'll scroll that one instead -- no clicking required.

I imagine this is a feature, but I'd never noticed it before. Could prove useful at times.

Try typing //Volumes/ in a browser window (I used OmniWeb, but they all should work). Pretty cool, it brings up the local filesystem so that you can navigate through it.

I don't know how useful it is, but sorta cool.

This probably goes in the category of "How come you didn't know that already?!" but I think it's worthy of a mention. I've started using OmniWeb (as of fc3) as my (nearly) full-time browser, so I'm just starting to learn its subtleties. One thing that bugged me in earlier builds was the layout of the navigation bar.

This morning, by complete accident, I noticed you can move the objects on the bar by dragging them with the "command" key held down -- cool! In addition, as pointed out in the comments, control-click in the nav bar in an empty location, and you'll see a sheet of further customization options. Very impressive!

I now have a layout that I find much more usable. As a general comment, I really like the latest OW, even though it does some not so good things on this page (the "Favorite OS X Apps" box gets muddled pretty badly), and I can't yet use it with my home banking service. It's very fast and stable, and the page rendering is beautiful! They'll be getting a check from me, as I like the idea of supporting Microsoft competition!