I recently booked a trip paying for my flights on Orbitz and my hotels on Expedia.
Both sites offer best price guarantees.
After booking, but within 24 hours of booking, I found slightly cheaper prices on both the flights and hotels.
I contacted both Orbitz and Expedia. They both refunded the price difference and both gave me $50 USD vouchers on top.
Not bad. Worth remembering if you book flights/accommodation.
+1 for this thanks.