Never too sure if this works out cheaper once you add in the credit card and other booking fees opodo adds in, but might be of some modest value:
Get £25 off AF KL DL bookings over £300 at http://www.Opodo.com
Code is airfrance.
Principal terms and conditions for e-voucher code ‘airfrance’:
The value of each e-voucher is £25 off flight bookings costing £300 or more on Air France, Delta or KLM airlines only.
Only one e-voucher may be used per booking.
Please note the e-voucher discount is redeemable against each booking, not each individual flight.
Your e-voucher must be redeemed between 24 September and midnight on 02 October 2009.
The number of e-vouchers coded ‘airfrance’ is limited and the e-voucher will only be valid if it is within the first 1000 bookings.
Should the e-voucher no longer be valid at the time you make your booking, you will be informed of this before the booking process is complete.
Full Ts & Cs at Opodo