Links: Some thought experiments
Wikipedia can be a very good time waster.
There's some interesting food for thought in some of these old chestnuts. Kavka's toxin puzzle is particularly relevant now that I've studied various kinds of criminal intent in law school. Quantum suicide is the topic of the novel "Quarantine" by Greg Egan, a little gem of hard sci-fi (you know, the kind without lightsabers and phasers ;=) ). Perhaps the most inscrutable, at least for me, are the pages dealing with the EPR paradox and the Renninger negative-result experiment.