SchoolShare is the RM product which enables peer-to-peer networking.
Torrents have largely replaced peer-to-peer networks as the preferred method of getting music for free on the Internet.
With the growing popularity of the Internet and peer-to-peer file sharing, the proliferation of free downloadable ROMs (usually in the form of ISO files) has also increased in popularity.
Popular sources include P2P (peer-to-peer) networks and newsgroups.
If you were to "rip" the video game ROMs from games you already own, you'd probably be in much better shape than taking the shadier means of peer-to-peer networks, bulletin boards, and the like.