Our Daily Bleg: What to Do in Madrid?

Am heading to Madrid tonight for the release of the Spanish edition of SuperFreakonomics. I will likely be in Madrid for the entire brief stay (here’s one event); I’d appreciate any good advice you may have, unlimited in scope. I’m sure we’ll see plenty of paintings and probably lots of unemployed people too; all further suggestions about what to see, learn, eat, etc., would be most appreciated. And don’t forget to send along your own blegs. (For those who don’t know: bleg = begging on a blog.)