Good news, Restaurant.com is once again a participant in the Hilton HHonors Earnings Mall.
Restaurant.com sells coupons which typically cost $10 for a $25 coupon to certain restaraunts; this $10 is frequently discounted by 80%. This means you get a $25 coupon for about $3, earn 10 HHonors points per dollar on your purchase, and keep your points alive.
I purchased and used a Restaurant.com coupon myself just last night. Be sure to note restrictions (days of the week, minimum purchase, etc.) which vary by restaruant.
http://www.hiltonhhonorsearningsmall.com
Direct link to Restaruant.com page at hiltonhhonorsearningsmall.com