Quickly look something up in wikipedia, a dictionary or whatever you like (its easy to add custom sites!). The result is displayed directly on the page.
Firefox with Greasemonkey: Greasemonkey script NoDelay allows you to bypass please wait, your download should begin shortly dialogs and begin downloading files immediately.
Computers make us more productive. Yeah, right. Lifehacker recommends the software downloads and web sites that actually save time. Don't live to geek; geek to live.
Firefox with Greasemonkey: Blogger Raúl Ochoa has created a Greasemonkey script that adds search to Google Reader by accessing the feed items synced with Google Gears.