A typical interaction is shown in the video; read the description below for an outline of the procedure.

The first study from HINTS investigated whether humans hold a humanoid robot morally accountable for harm that it causes. The robot in question is Robovie, the little guy (little piece of equipment?) in the picture above, who was secretly being controlled by humans throughout the duration of the experiment. The experiment itself was designed to put a hapless human in a situation where they would experience Robovie making a false statement, and see how they'd react: would Robovie be responsible, or simply a malfunctioning tool?

To figure this out, human subjects were introduced to Robovie, and the robot (being secretly teleoperated) made small talk with them, executing a carefully scripted set of interactions designed to establish that the robot was socially sophisticated and capable to form an increasingly social relationship between robot and human. Then, Robovie asked the subject to play a visual scavenger hunt game, with $20 at stake: the subject would attempt to find at least seven items, and if Robovie judged them to be successful (that's an important bit), within a 2-minute time limit, they'd get the money.

The game, of course, was rigged.

Overall, the study, funded by the National Science Foundation, found that:

65% of the participants attributed some level of moral accountability to Robovie for the harm that Robovie caused the participant by unfairly depriving the participant of the $20.00 prize money that the participant had won. ...We found that participants held Robovie less accountable than they would a human but more accountable than they would a machine. Thus as robots gain increasing capabilities in language comprehension and production, and engage in increasingly sophisticated social interactions with people, it is likely that many people will hold a humanoid robot as partially accountable for a harm that it causes.

Science fiction writers have spent some time exploring these topics. In the sequel to Stanley Kubrick's 2001, Dr. Chandra learns at last why the HAL-9000 computer exhibited unusual behavior in the earlier film 2001: A Space Odyssey. (SPOILER!)

(From 2010 - HAL tries to lie)

"... he was given full knowledge of the two objectives and was told not to reveal these objectives to Bowman or Poole. He was instructed to lie...

The situation was in conflict with the basic purpose of HAL's design - the accurate processing of information without distortion or concealment. He became trapped... HAL was told to lie - by people who find it easy to lie.

The Bolo autonomous tanks from Keith Laumer's stories evolved to become robotic exemplars of military virtue.

In the 1982 movie Blade Runner, the replicant (non-robotic, but an artificial human) Roy Batty is given the choice to let his enemy, the human detective Rick Deckard, die, Batty instead chooses to save him.

(Roy Batty debates saving Rick Deckard in Blade Runner)

Ethical dilemmas for robots are as old as the idea of robots in fiction. Ethical behavior (in this case, self-sacrifice) is found at the end of the 1921 play Rossum's Universal Robots, by Czech playwright Karel Čapek. This play introduced the term "robot".

Update: For a hilarious counterpoint to this article, take a look at this video from the British TV series Red Dwarf in which Kryten the robot is taught to lie. You'll love Kryten's reasons for wanting to lie, and Dave's reasons for teaching him. End update.