Just noticed this one while surfing the AC site and thought it worth sharing.
http://www.aircanada.com/en/offers/a.../websaver.html
*Sample fares shown for international destinations are round-trip and subject to availability. Fares shown to Europe must be booked by November 18, 2005 and are valid for travel until December 15, 2005, unless otherwise specified below, with no advance purchase requirements.
- Other international fares shown for must be booked by November 10, 2005 and have an advance purchase requirement unless otherwise indicated below. Tickets dates vary as indicated below. Other conditions may also apply:
London: Fares shown are valid for travel from November 2 to December 16, 2005. Saturday night/Maximum stay: 12 month.
Amsterdam/ Barcelona/Brussels/Copenhagen/Düsseldorf/ Frankfurt/Geneva/ Hamburg/Madrid/Munich/Paris/Prague/ Stockholm/Stuttgart /Zurich: Fares shown are valid for travel from November 2 to December 8, 2005. Minimum stay: Saturday night/Maximum stay: 2 month.