Secret Santa is a form of communal gift giving, that I have seen being done at workplaces to foster closer ties to employees. It is generally done near the end of the secular year. While the wiki article says that it's often voluntary, everytime I've seen them, the voluntary nature of it was not very clear, and it felt pretty obligatory to me.
While one can't give a gift to a non-Jew 3 days before their holiday, how does that halacha apply to this situation? Also what other relevant halachot are there? Does it matter if the instigator of Secret Santa is Jewish? Does it matter if there are other Jews in the group besides yourself?
Related to this question.
Mystery Maccabee
along the same lines... (where quite a few of the workers were not jewish)