Connected Histories now has a search box that you can add to your own website or blog. You can see it in action in the sidebar to the right – give it a try!
The code to copy and paste can be found here. It works on Blogger blogs but I’m not sure if it will work on wordpress.com because they strip out scripts. If you can’t include the search box or don’t have the space for it, there are also options for simple HTML links.