[mixmax]

Slashdot had something similar many years earlier

[ryandrake]

I think they even called it Karma--back in the late 90's. I bet that's where the term originated.

[masterofmisc]

Gee, Slashdot. That brings back memories

[dredmorbius]

Slasdot had karma, Kuro5hin had mojo.