CABPedia
The link is a little bit buried in a previous post, so I decided to highlight it in a specific post (thanks Matias :-)).
CABpedia is a wiki mainly covering CAB, SCSF and Mobile Client SF. And although not a patterns & practices or a Microsoft official site, it is full of good content. John Socha, Matias Woloski, John Askew, Mariano Szklanny are some of the frequent contributors and all of them are experts on the subject.
If you have something good to share, this is probably a good place to start.
http://www.cabpedia.com
