Nuclear Elephant have set out to prove something that the P2P community has known for a long time - "illegal" file-sharing actually encourages CD sales. They've invited people who've bought a CD/movie/software after downloading a pirated copy online to submit a testimonial and the amount they've spent. (So far its $138,974 and counting)...
In the case of music, the so-called "pirates" routinely purchase CDs of stuff they've downloaded because its better quality than the mp3s, or because they love it and understand that the outlay of money will help keep the artist/label viable... For small boutique labels (who would previously have had very limited opportunities for exposure) it represents a positive boon...
So, the only people it really harms are Big Labels who try to foist disposible chart-fodder on an increasingly discerning record buying public... And they can muck out the monkey stalls at the zoo for all I care...
If you've purchased anything as a result of your exposure to it via P2P, I encourage you to enter the details on the Nuclear Elephant site. (Don't worry, names and IP addresses aren't saved, so you will remain anonymous.)