When searching on SharePoint 2007 server or SharePoint 2010 Server, a full enterprise search is performed. The results are across the whole web site.
To perform a search, you press the phone's search button after connection to a site. This will show the search bar at the top of the screen to allow you to enter a keyword to search with. Once the search is performed, the results are shown on the screen. The documents that are listed in the results can be acted on just like documents within a library.
Pressing on a document title will view the document, and pressing and holding a document title, will show a menu of actions that can be performed on a document.