Because of the anime, dgm has been seen in many various items besides trading cards. So maybe we can showcase them on this thread if we come across something?
Cell phone charms and holders
D.Gray-Man merchandise on Shueisha
Calenders '07 (flash-site, skip and then click on dgm)
mobile phone goodies (certainly not free)
I found a website with all of the dgm goodies (including cosplaying materials :amuse):