For fun I've run my BL5s from my iPod. Works nicely, though you have to have the BL5s off when connecting if you want to try it. (Impedance blasts while connecting can destroy your tweeters if you don't.) And don't disconnect while playing.
The chap in London story I heard had a man coming to a B&O dealer, and asking whether the BL5s were as good as he'd been told. He had the dealer connect his iPod to a pair, and bought them on the spot.
BTW - the digital-to-analog converter in a regular iPod is not good enough to get even close to what BL5s can do - and when you turn up the volume you'll hear hiss in quieter portions of your music. What you should do is get a converted iPod with iLink from msb Technologies:
http://www.msbtech.com/products/iLink_web.jpg
This has digital out, which you can then connect to the digital coax in of your BL5s. Then it's the DACs in the BL5s you are using. Store lossless music on the iPod, and you have the convenience and fun of a really small source delivering a blast of uncompressed music.