In my article Tafiti and Windows Live Quick Apps, I told you how you can do a search project with one, or more, of your live Messenger contacts with Tafiti search Visualisation. There's another method to search together coming this Spring, it is called Microsoft SearchTogether.
Microsoft SearchTogether is a free Internet Explorer 7 plug-in which will allow you to search various search engines (Windows Live Search, Yahoo!, Google etc.) together. Features are group query histories, split searching, page-level rating and commenting, automatically-generated shared summaries, peek-and-follow browsing, and integrated chat at the bottom of the browser. More about installing and these features can be found in the tutorial.
SearchTogether will be available for download this Spring at http://research.microsoft.com/searchtogether/ and was shown at Microsoft's annual TechFest by Microsoft Research.