This script was originally written by Michael Shepanski and posted here:
http://pushingkarma.com/notebook/setup-dynamic-dns-using-linode/

I've made some tweaks and dropped it in git for anyone else that's looking for
the same kind of functionallity.  Needs the pycurl python module as well as the
linode api found here:
https://github.com/tjfontaine/linode-python