Friends of the Stanford Encyclopedia of Philosophy
The Stanford Encyclopedia of Philosophy is to date the most visible and successful experiment in "open-access" -- that is, free -- academic philosophy. (This isn't to say there aren't also other excellent open-access resources like Philosophers' Imprint and various archiving projects.) Fans of open access who loathe the finacial abuse of academic libraries at the hands of companies like Springer might consider paying the modest fee to support the Stanford Encyclopedia: $5 per year for students, $10 or $25 for others. Who'd've thought you could buy friendship so cheaply?
The SEP is trying to entice people to join by offering their "friends" access to handsome PDFs of SEP entries. Maybe that kind of thing appeals to you, but for me it's just a matter of supporting a cause I care about.