on http://sourceforge.net/projects/bitcoin/files/Bitcoin/bitcoin-0.8.1/ there's no source code tarball which i need to get reproducible results on my build-it-yourself distro (package management system is laid out for source tarballs with checksums, not git checkouts)
apparently the linux download has the source included, but also comes with prebuilt binaries (unusable in my case, since i use a different libc). this bloats up the tarball to twice the needed size or more, which affects download time and hd usage. the argument that 18 MB is nothing compared to 7G of blockdata, is not valid for people who just fetch all tarballs in one go (so they have them already in case they need it), but in the end do not use the bitcoin client.
so please in the future release a separate source code tarball and make it available from the default download page. thanks.
please also consider using the .xz compressor since it's about 40-60% better in compression and only slightly slower in decompression speed than .gz (but 3-4x as fast as bz2) and available on any linux distribution that came out in the last 5 years. even busybox supports it by default.