After rebuilding my VirtualBox Debian Lenny development images to 64bit installations, I realized that I needed to update my Debian personal package repository to include the amd64 architecture. So! I went ahead and rebuilt the latest packages from Squeeze for amd64 and i386 for Lenny, which includes Lighttpd at 1.4.28.
The following packages from Debian Squeeze are now in the PPA:
erlang-1:14.a-dfsg-2~bpo50+1 [amd64, i386]
couchdb-0.11.0-2.1~bpo50+1 [amd64, i386]
lighttpd-1.4.28-1~bpo50+1 [amd64, i386]
dkimproxy-1.2-6~bpo50+1 [amd64, i386]
UPDATE! 2015-06-04: I no longer maintain this Debian PPA.