Google Chrome: Setting a website to refresh is old hat, but what if you want to refresh multiple sites and keep an eye on all of them? Revolver-Tabs refreshes and rotates your browser tabs.
Revolver-Tabs is a Google Chrome extension that allows you to refresh not just one, but all of your browser tabs, at set intervals. In addition to reloading the page it rotates through the tabs one by one so that the individually refreshed sites are displayed without any interaction from you.
Although the author designed the extension to be used for stand-alone kiosks or during presentations — both great uses for it — it's also just as useful for keeping tabs on auction sites, status and announcement pages, and other frequently updated sites without any interaction. It's a great candidate to get tossed on your second monitor for watching sites that don't have RSS feeds or that you want to get immediate feedback from without waiting for RSS delays.
If you're a Firefox user make sure to check out Reload Every, you can set the frequency of reloads but can't set the tabs to rotate. Have an extension or bookmarklet that makes your web browser even more useful? Let's hear about it in the comments.