caimsfiredragon377, you may adopt a Pokemon from these two places.
PokeZoo Adoption Center
Dragon Tamers Adoption Center
The links on the main page may be old.
Just in case you were wondering, the capture centers are here:
Pokemon Avengers Capture Center
Crystal Caves Capture Center

To adopt a Pokemon, simply post in one of the two adoption centers and say that you want to adopt a Pokemon on the list that is still available and has not been adopted.

EDIT: Yes, the links are old. Can a mod update the links? PZAC links to version 25 and DTAC links to version 3.. I believe.
It's a version older than they are.
I'm not sure of the other links, but they may just be old too, especially the GT considering the fact that a version 30 was just posted.