IG Sites

Confirmed

aladygma.com
becroad.de - hosts Thomas' journal

Debunked

...

unknown

amgydala.com - appears unconvincing and offers no added information
3sat - nano: "Virales Marketing. Die Macht des Internet." Contains new white space /evl/
a-l-a-d-y-g-m-a.blogspot.com/ - appears canon as of this comment on Thomas' blog

OOG Sites

Wikis

[Wetpaint-Aladygma - this is what you are looking at right now!]
ARGR Wiki - Aladygma by Patrick Möller of patmo.de, unused, need registration, German language environment

Blogs

AladygmaClues - by Nick Butler
aladygma.blogspot.com/
Aladygma - Cloverfield - United World - "Aladygma Hunter Germany." (Counting down to 2012-12-22T00:00 - end of the world by Mayan calendar?)

Forums

AladygmaClues/Forum

Articles
see the mysterious 3sat-nano article under "IG Sites", 2008-05-16
ARG Reporter article by Patrick Möller, 2008-03-28