Originally Posted by muji

Get a free anti-snoring sample here:
http://www.breatheright.com/Default.aspx
Then offer it to them.

Or...accidentally bump into or elbow them - this can at times calm the snoring, at least for a short period of time.

Better yet, bump into them really hard (or spill a drink on them), again accidentally, so that they become quite awakened. In the awakened state they will not snore.