Concatenate lists with LINQ
<p>Is it possible to concatenate a <code>List&lt;List&lt;T&gt;&gt;</code> into a <code>List&lt;T&gt;</code> with a single operation in a way which isn't horrible slow, i.e:</p>

<pre><code>List&lt;List&lt;int&gt;&gt; listOfLists = new List&lt;List&lt;int&gt;&gt;();
List&lt;int&gt; concatenatedList = listOfLists.Something...
</code></pre>

<p>?</p>
