Snap is a nice little search engine which displays your results in a left window pane and a site preview of your search result in the right. It’s very Ajax-y and includes personalised settings, email a friend, result ratings and more. They even made the Time 50 coolest websites of 2006.
Snap is also a free preview tool for your website which enables visitors to catch a glimpse of what websites you are linking to. All you need to do is hover your mouse over a hyperlink to see a thumbnail of the linked site.
I’ll admit that this one is a bit gimmicky but it’s still kind of fun :)
By default snap only gives you previews of external URL’s, but you can turn on internal URL’s as well as play with a few extra options. See their FAQ’s for more.