Windows/Mac/Linux (Firefox): Fireclip, a free plug-in that monitors specific sections of web pages, puts the at-a-glance convenience of the OS X widget screen in a Firefox tab.
Using Fireclip is darned easy. Activate with a shortcut (Alt+Q) or from the Tools menu, and its sidebar pops out. Hit “Select Clip,” and you can mouse around to see the pre-defined sections of the page. Click once, and you’ll be asked to re-size your selection with the familiar two-directional arrows at the edges of your area. Double-click inside the area, and it’s locked in:
You don’t have to be precise at all with your selections, so leave any dead space or visual cues you want around the edges. Opening Fireclip’s page with the same shortcut gives you a space you can re-arrange however you’d like with your clips:
So, okay, Fireclip actually works and all, but what use would it be to the average surfer? Amit Agarwal’s screencast of Fireclip might explain it better than my words:
Fireclip is a free download, works wherever Firefox does. I encountered a recurring pop-up ad while launching the clips page, but wasn’t sure whether it was Fireclip itself or one of my clips.