WSS Search across SiteCollection : Search Server Express 2008

By default in WSS, you cannot search across site collections without having MOSS features. for example, from Sales Site Collection you cannot search data in Marketing Site Collection.

By using Microsoft has released Search Server Express 2008 we can search across multiple site collections by without using MOSS features. Search Server Express 2008 is a free product from Microsoft.

for more information http://www.microsoft.com/enterprisesearch/serverproducts/searchserverexpress/default.aspx