I've been giving my data to Last.FM for years - it's time I cashed out on this investment and got my data out, so I can make some pretty visualizations.
I hacked up this script to get all my scrobble information, and make a playlist of each day.
After running it, you have a JSON representation of all your scrobbles in a big
array (containing all the information pulled form the Last.FM API), in all_scrobbles.username.json.
And you also get a text file for each day containing what you listened to that
day, named like 2010-12-14-username.txt, and containing lines like
2011-03-23 17:48:43 - Passion Pit - Manners - Seaweed Song.
Usage:
./get_lastfm.py <yourlastfmusername>