CheapTickes currently has a promo where you get between $30 and $15 of its "currency" CheapCash for each flight you book. This CheapCash can then be used within 30 days to book hotels on CheapTickets (and $1 in CheapCash is worth $1 in USD). Works even for chain hotels which usually are exempt from regular coupon codes.

I found some one-way flights priced at slightly over $50 (for example Istanbul to Berlin in November) which give full $30 in CheapCash. So this can be quite an awesome deal. (it might be worth to split a rt into two separate one-ways, depending on the fare pricing).

Here is the URL explaining the campaign http://www.cheaptickets.com/mktg/CheapCash/

There is some fineprint at the bottom.