Hey, I am Frog23 and I am mostly active on the German Wikipedia.
I developed a Script called DeadLinkFinder which automatically checks all the links on the current Wikipedia page one is surfing on and reports if any of these links are dead. A details English description on how to use the DeadLinkFinder and how it can be customized can be found here: http://de.wikipedia.org/wiki/Benutzer:Frog23/Dead_Link_Finder/en