So I had a go. It's interesting, it seems like it could be useful but it's not really going "Here's some Ruby stuff that's useful on a daily basis" and it's more copy this line as well as you can in 10 minutes. It might help with muscle memory learning, but I didn't feel it helped get my brain anymore Ruby geared. YMMV.
I get a blank page here: <a href="http://drills.learncodethehardway.org/python/" rel="nofollow">http://drills.learncodethehardway.org/python/</a> in Safari 5.1.5 on OS X 10.7.3