RemExternalLinks -- Script for use in removing external links from a specified domain. Works by going to the Special:Linksearch page and entering in a search. From there click the tab, and it will highlight the links green. Click the links and the js will automatically do the work of removing the link and show a diff. (made by en:User:GeorgeMoney}
Heligoland/link -- excellent statistics and graphs on the rate of spam. Updated frequently.
Veinor/Link count Data showing how many times a domain was linked-to (different subdomains are distinct), who linked to it, and how many times they did it.
Search the archives; currently, only displays the link count added between the two days and has no regex capabilities.
ReyBrujo/Dumps -- Currently has pages (or links to subpages of this one) with greater then 50 links on them. Data was gotten from a database dump. The date of the English Wikipedia dump was November 30, 2006. Use the interwiki links to access statistics in other Wikipedias.