EzineDepot -E-zine and newsletter directory and search engine.
FindMail -List serve
GlobeLists -Email discussion groups
Impulse -Email discussion groups
List of Lists -List server index/ SE.
List Universe -Resources. Search its New Lists.
Lists Net -Directory of over 2,000 mailing lists.
Liszt -List server index/ SE.
LSoft -
PAML -Publicly Accessible Mailing Lists.
Tile.Net -List serve info.
Topica -List server with 50,000 lists. Very user friendly. Hosts some nice specialty lists such as AllSearchEngines!
Yahoo! Groups -List server has more than 300,000 groups.