i used the address on the database which is:
Futurama
P.O. Box 900
Beverly Hills, CA 90213-0900
USA

Hi mrfuturamamad101 :)

Thank you for your feedback {up}

At which address did you send your autograph request please?

{star} [url=http://www.fanmail.biz/2460.html]Futurama[/url] on Fanmail.biz

Fanmail 8)

Sorry that it wasn't signed, none of the cast are great signers at all. Some of them you can buy their autographs through their website though.

I sent a letter and photos to the cast of futurama some time in september 2011. Today on the 17/7/12 I recieved a letter from the assistant of David.X.Cohen and a photo which was unsigned :(

Envelope:
http://imageshack.us/photo/my-images/824/futuramaenvelope.jpg/

Letter:
http://imageshack.us/photo/my-images/824/futuramaletter.jpg/

Photo:
http://imageshack.us/photo/my-images/32/futuramapic.jpg/

Oh well, i'm still gratefull that i got a reply :D