OpenStreetMap
I confess to putting an Easter egg in the OpenStreetMap of the Vienna suburbs (http://openstreetmap.org/?lat=48.22152&lon=16.29188&zoom=17&layers=0BFT).
(Clue: One of the streets may have the wrong name.)
To eliminate it: go there and do your own survey! Do not corrupt your mind by looking at a commercial street map!
Discussion
Comment from Teaandkale on 18 April 2008 at 12:12
You're not the only one. Try searching 'carpal way' on the OSM homepage. ;)
Comment from nickw on 22 April 2008 at 18:17
I admit to naming a street in Southampton "Innominate Road" for a while. Not really an Easter egg, just fed up of constantly encountering missing road signs round here....