Speaking of 2005 Yahoo deals, here is another: del.icio.us sells to Yahoo. Not a good sign that my original Yahoo and Del.iciou.us announcement links both return error pages now. Internet Archive saves the day ( and history ) yet again.
This lasted six years, after which Yahoo sold Delicious to the founders of YouTube ( in 2011 ).
Based on my personal usage, I’d grade the Flickr purchase better than the Delicious one. I still use Flickr, but haven’t touched Delicious in a very long time.