Hotel Club are offering a £25 immediate credit for new members who sign up and a further $10 off your booking for any hotel stay til 31 december 2008.No minimum spend or nights at all.

Here is the link for the £25 for joining http://www.hotelclub.co.uk/tube/

The other link for the $10 after you've signed up is...........http://www.hotelclub.co.uk/Birthday/

Not tried this but you might also get £15 cashback through Cashbackkings.
http://www.cashbackkings.com/hotelclub.com-uk/bargains/b60708