Let's take a look at a possible "microapp" you can do with federated search in Windows 7...
How about having a way to very quickly search tweets for a keyword or a mention and then save these searches to allow one-click access to quick glances on Twitter activity?
Easy with Search Connectors 
Open your favorite text editor and paste this bunch of XML:
<?xml version="1.0" encoding="UTF-8"?>
<searchConnectorDescription xmlns="http://schemas.microsoft.com/windows/2009/searchConnector" xmlns:atom="http://www.w3.org/2005/Atom">
<description>Twitter</description>
<isSearchOnlyItem>true</isSearchOnlyItem>
<domain>http://twitter.com</domain>
<supportsAdvancedQuerySyntax>false</supportsAdvancedQuerySyntax>
<templateInfo>
<folderType>{8FAF9629-1980-46FF-8023-9DCEAB9C3EE3}</folderType>
</templateInfo>
<locationProvider clsid="{48E277F6-4E74-4cd6-BA6F-FA4F42898223}">
<propertyBag>
<property name="OpenSearchShortName"><![CDATA[Twitter]]></property>
<property name="OpenSearchQueryTemplate"><![CDATA[http://search.twitter.com/search.rss?q={searchTerms}]]></property>
<property name="MaximumResultCount" type="uint32"><![CDATA[100]]></property>
<property name="System.PropList.ContentViewModeForSearch"><![CDATA[prop:~System.Contact.FullName;~System.DateModified;~System.ItemPathDisplay;~System.Search.AutoSummary;~System.Author]]></property>
<property name="PropertyMap"><![CDATA[<PropertyMapList>
<PropertyMap sourceNameSpaceURI="http://base.google.com/ns/1.0">
<Source path="image_link">
<Property schema="http://schemas.microsoft.com/windows/2008/propertynamespace" name="System.ImageParsingName" />
</Source>
</PropertyMap>
<PropertyMap sourceNameSpaceURI="http://www.w3.org/2005/Atom">
<Source path="author/name">
<Property schema="http://schemas.microsoft.com/windows/2008/propertynamespace" name="System.Contact.FullName" />
</Source>
</PropertyMap>
</PropertyMapList>]]></property>
</propertyBag>
</locationProvider>
</searchConnectorDescription>
Save this in C:\<username>\Searches (or wherever your user profile is) as twitter.searchConnector-ms.
Then go there, double click it and enter something in the search box, say... "channel9".
Marvel at the fancy results, click on Save Search and name it "Channel 9 on Twitter". A shortcut is the created in your Favorites node in the navigation pane on the left.
Now, whenever you want to check the last 15 mentions on "Channel9" on Twitter, just click on that shortcut, glance at the results and go back to your task.
This was a presentation from the Find & Organize chaps 