This was a pretty fun hack I did back in 2006 while at Yahoo as part of a hack day.
Yahoo! Answers was pretty fresh on the scene and I found one friction point was easily inserting URLs or HTML links to a text box or text area. You had to leave the page you are on, do a search, often click through, then save the URL and come back and add it to the text box
Select text in the text box or text area, hit the Linker bookmarklet. Lightbox appears next to the text area with search already populated for what you selected. Search box is fully keyboard traversible. Scroll up and down and hit enter to add the text and dismiss the lightbox. Can insert as straight URL or insert HTML for an tag with the URL in the href.
This add to the repository is just my desire to get this off of some local drives and off of CVS into github. So this probably doesn't work as it sits today. I plan on moving this out of PHP and YUI 2 over to Kraken & jQuery.