The kindness or cuckoldry of strangers

We're still in the era of prankdom, when people can win $100 if they go along with a stranger's protracted back story and subsequent request for help (thank you, "Boiling Points"). It seems that ever since hitchhiking became taboo (but there's hitchwiki!), we redirected our thirst for those encounters into a devoted voyeurism that finds relief in reality television, especially that of the "reveal"-oriented variety.

Every time I see a show that hinges on the horrified reaction of a reveal, I experience a moment of complete chagrin (at my industry) and complete empathy (for the talent). But it's hard to turn away from shows that examine our willingness to comply with strangers in apparent need. "Boiling Points," sure, but I've also seen the nightly news send reporters out to demonstrate how we're more likely to lend assistance to attractive strangers (all of this still aftermath of Stanley Milgram and his 1974 study, "The Perils of Obedience," proposing that attractive people were more likely to attract help and less likely to become victims).

So: what's the most you've ever complied with a stranger, and have you ever been burned or perhaps even assisted by the encounter?