Some of the hottest tickets in town are to Harvard commencement events featuring two famous Bills: Clinton and Gates.

Dozens of Harvard University students sold free tickets to events for as much as $100 a piece, much to the chagrin of university officials.

"We obviously frown upon it and do what we can," university spokesman Joe Wrinn said.

The tickets, listed for sale on Craigslist.com, were to Wednesday's Class Day talk by former President Bill Clinton and Thursday's commencement address by Microsoft Corp. founder Bill Gates.

Scalping tickets to free events has gone on in the past, but students have taken the practice to a new level this year because of the high-profile speakers.

"Harvard always has pretty compelling speakers, but with the two Bills this year, it's certainly quite unusual," said Ryan Spoering, resident dean of Lowell House.

Spoering sent an e-mail to the 450 residents warning them not to sell tickets online or they would face disciplinary action.

"If you have extra tickets, please give them to your blockmate's grandmother. For free," he wrote.

Students are given a certain number of tickets for each event, which they are supposed to give to family and friends. They are told when they get them they are not to be sold.