At the end of the day, P2P networks work. Sometimes all too well. Although friends may encourage you to hop aboard the “free music gravy train,” remember what you're jumping into. Beyond legal issues surrounding this dynamic type of data exchange, you may have to contend with software headaches that would not have plagued you, had you not opened your computer to these various file-exchange systems. If you want to “try before you buy,” you'll find that many “official” sites allow you to sample tracks or demo software.
It's what all the cool kids are doing.