Starting January 2013 the miles of the Alitalia frequent flyer program will be accumulated in a new program and will not add to the previous ones.
There it is still time to spend them until June 2013 according to the email I received.

I’ve decided to donate them to my preferred charity the Fondazione Banco Alimentare Onlus.
It’s as simple as sending an email to clubMilleMiglia.charity@alitalia.it (as long as you have at least 10.000 miles in your account) with the following data:
Your Millemiglia code
Your first name and last name
The amount of miles that you want to donate
The desired charity from the list available on the Alitalia site: Fondazione Banco Alimentare Onlus in my case.

If you live in Italy don’t forget Saturday November 24th to participate in the Colletta Alimentare Nazionale. I’ll be volunteering here most of the day if you are in the area just drop by.