We empirically test different voting rules on the allocation of public projects in a laboratory experiment. Specifically, we ask whether voters try to manipulate the outcome to their benefit. The mean rule, according to which the average allocation is chosen, is highly manipulable theoretically, and we find indeed that subjects have a strong tendency to play the corresponding (non-truthful) Nash equilibrium strategy. By contrast, median-based rules are more difficult to manipulate, and sometimes truth-telling is in fact a weakly dominant strategy. The behavior of subjects is more subtle here and, surprisingly, also more difficult to predict. While most subjects play a best response to truth-telling of all other voters, a significant fraction of them does not vote truthfully themselves. We also find that the voting rule has a significant impact on the frequency of Nash-play, truth-telling and the extent of deviation from the truth.