BitTorrent isn't really a P2P program like the others, but there are several websites that you can use to search for files. From there you can download the files at speeds generally better than what you get off of something like Kazaa.
Kazaa has been busy running around shutting down any other programs that use it's network, including Kazaa Lite. You can probably still find a copy somewhere, but eventually they will change something that will prevent it working anymore.
goates