The Windows Live folks are now providing a search box that you can use on your website. It comes in two versions: a very cool AJAXy version that displays the results in an overlay box right on the page and is highly configurable, and a simpler form-based version that helps you search your site on Live.com. The advanced version is great; besides the overlay box, it lets you search up to 10 sites, or via a Search Macro (or both). I’ve implemented it on this page, searching all my sites, so enjoy it.
There are also some options for hacking and extending the search box, one of which I’ve implemented here. Anyone want to guess what it is?