This Mother's Day, call any phone, anywhere in the world for free with Skype.

[HeatSeeker]

Taken right from their site:

This Mother's Day, call any phone, anywhere in the world for free.

1. Offer valid from May 13th 2007, 5.00 am (Eastern Time GMT-5.00) to May 14th 2007 4:59 am (Eastern Time GMT-5.00).
2. Offer reserved for residents of the US and Canada. During the offer, calls originating from the US and Canada placed to mobile and landline telephone numbers will be free.
3. Calls to premium numbers and satellite phones are excluded. SkypeOut calls made as a result of using the "call forwarding" feature are excluded.

Linky