Today, while waiting to watch K-ON, I occupied myself with various real life attempts to bring the OP and ED to life. Quite surprisingly, after merely 4 weeks of airing, there's so much stuff out there its hard to imagine that most of the people who watch K-ON aren't exactly musicians. Furthermore, it seems this anime has had the effect of driving up guitar sales in certain places too. Oh well. This post contains some of the better K-ON music videos of people playing the OP and ED.
Ok this one isn't exactly the best out there... but violin...?
Also, omfg wut? Piano hero?
And finally, just for the lulz