Deletionpedia attempts to capture the tens of thousands of pages that have been deleted from Wikipedia for one reason or another. It sometimes misses the odd one but hey, look, the page I started on Lukas Rossi is still going strong!
If you didn't read it the first time I posted it, you should also definitely check out Nicholson Baker's piece on Wikipedia which talks about their deletion mentality. Baker is already well-known in libraryland as an advocate for preservation of books and newspapers by libraries in an age of digitization.