I used the RSSBus WebPart to create a multi-source search in SharePoint – this will let me enter one search term, and see results from a variety of different search services at the same time. The RSSBus WebPart template turned out to be extremely simple, thanks to its built-in feed manipulation capabilities.
The first 5 lines are just HTML to create a search query text box and submit button. I don’t use a form tag, I just piggy back on the existing form that is in every SharePoint page. Next, I check to see if the search input variable exists in the form of the incoming HTTP request. If so, I set my source feeds, call for the union of the feeds (duplicates are automatically discarded), and output some html for each result!