If you use Google Reader, here is a script to backup your subscription list (titles and URLs of subscribed feeds) automatically, e. g. from cron or a scheduled task.
Is it just me or was backing up all your data easier in the old days? Back then, you simply copied files from one machine to another. While this principle still holds true, nowadays my data is literally spread across dozens of machines, each requiring a different login mechanism and credentials. I don’t want to back all of this up, but I prefer to do so if 1) it’s easy to do so or 2) the data is hard to regenerate.
Enough talking, it is easy to schedule an export of your subscription list to OPML, so there is no reason not to do it. The attached script takes two parameters (username and password) and spits out an OPML file – obviously, this should probably be redirected to a file. I call it like this:
gr-opml-backup.py myUserName@gmail.com myPassWord > google-reader-subscriptions.opml
Not sure about the system requirements, but my guess is that any version of Python from 2.3 to 2.6 will be fine. All credit should go to gPowered for providing the Google Reader API library for Python – thanks!