This is a modified version of Launchpad-getkeys with experimental proxy support added.
(see http://www.webupd8.org/2010/05/automatically-import-all-missing.html)

The changes have been merged back. Please see http://www.webupd8.org/2011/02/launchpad-getkeys-gets-proxy-support.html now.

Usage:
First you need to run sudo visudo.
Add the line:
Defaults env_keep = "http_proxy"
above the line:
Defaults        env_reset

Save the launchpad-getkeys in your path and run:
sudo launchpad-getkeys

You can specify the keyserver and the proxy server with -k SERVER:PORT and -p http://SERVER:PORT commandline args respectively.