And no, we're not talking about the Playboy ones. It's hard not to notice that celebrities have been wearing something different on their heads lately: bunny ears.

It all started on the Louis Vuitton runway earlier this year (doesn't Sasha P look cute?) and has spread into the real world thanks to Madonna's appearance at the Met Ball. Then there were the paparazzi shots of Lily Allen, Lady Gaga, the Olsen twins...

Perhaps this is only a natural escalation from everyone copying Blair Waldorf's headbands.