There’s now a mysterious magnet icon next to each track’s download link. If you click this icon and have the appropriate P2P client installed (LimeWire, Morpheus, Kazaa, BearShare, Shareaza, others — see legend at http://creativecommons.org/... for links), your client will attempt to download the track via P2P and unless you’ve configured it differently, automatically share the download with others.

If you don’t know or care about filesharing just ignore the magnets, they don’t bite.