I was reading the Wintellect blog and came across this post from John Robbins (MSDN Magazine's Bugslayer) describing a VS.NET addin named Solvent. Solvent adds a couple of much needed options like recursive expand/contract to the Solution Explorer context menu. Also added to the Solution Explorer menu are "Open Containing Folder" (in an Explorer window) and "Command Prompt Here".
If this isn't enough, he's also written an addin named CR_Documentor which displays XML Doc Comments for the current source file in real time in a tool window (naturally, in nice readable formatted HTML).
I've installed both of these, they are both pretty handy utilities.