Book 2 or more nights at any of the Corinthia Hotels and get 50% off your stay! The deal is valid for stays up until the new year!
This may be limited in the number of people that it will appeal to but I think it's a pretty good deal. I just booked 2 nights in the 5* hotel in Lisbon for 85 euros
They have hotels in Malta, Prague, Lisbon, St Petersburg and Budapest
Follow the link in the post then click on the more tab of the hotel you're interested in. Then click book now on the right hand side. It's important you do it this way because if you use the calendar search function on the left hand side the discount isn't applied.