apt-get update: pgp public key

[Chris Wakefield <c_wakefield@shaw.ca>]

Hi all.

I notice an error now when I run apt-get update:

"W: GPG error: http://debian.csail.mit.edu sid Release: The following 
signatures couldn't be verified because the public key is not available: 
NO_PUBKEY E415B2B4B5F5BBED"

Is there are apt-get facility to create a GPG public key?

Thanks for any info to make this easier to deal with,
Chris w.