Which keyserver to use for debian?

[Kent West <westk@acu.edu>]

I'm getting the "public key is not available" type error on trying to 
upgrade my box from lenny to squeeze.

I have a vauge understanding of gpg/public keys/private keys, but only 
vague, and I've found these two commands online which I believe will fix 
my problem:

gpg --keyserver subkeys.pgp.net --recv-keys 55BE302B

gpg -a --export 55BE302B | sudo apt-key add -

(where 55BE302B is the last half or so of the pubkey that is listed in 
the error)

My problem is that I don't know what keyserver to use. I have no idea if 
"subkeys.pgp.net" is a safe keyserver. So I've been googling for 
something like "official debian keyserver", or any keyservers on the 
debian.org domain. I found keyring.debian.org, but it doesn't know of my 
missing key, and I get the impression it's a limited keyserver for use 
by debian developers.

So, how do I know subkeys.pgp.net is a safe keyserver? Or is there an 
official keyserver for debian users?

Thanks!

--
Kent