I really don't understand what is the point of such entries. Everybody knows stack overflow. Putting a link to a tag on SO is not really something worth sharing.
There is also the NIST's Dictionary of Algorithms & Data Structures, which is formatted a little nicer. These are mostly 'textbook' algorithms though, probably not as specific as most of whats on StackOverflow<p><a href="http://xlinux.nist.gov/dads/" rel="nofollow">http://xlinux.nist.gov/dads/</a>
The Stony Brook Algorithm Repository is a nice little collection of algorithms, plus they out link to various implementations:<p><a href="http://www.cs.sunysb.edu/~algorith/" rel="nofollow">http://www.cs.sunysb.edu/~algorith/</a>