There is a new incentive network on the scene funnily enough called The Incentive Network.
They currently have 4 sites that you can sign up to they are
Each site currently has the same 9 offers, with more to be added in the next couple of weeks.
Also as a launch promotion they are giving everyone who signs up and completes 1 offer the chance to win 1 of 2 8GB iPhones, If you sign up and complete an offer on all 4 sites this then gives you four chances of winning 1 of the iPhones.
The competition will be run on the basis of the first 200 people who sign up and complete an offer will be entered into the draw so its first come first served competition, You can check out how many places are left here.
This promotional competition will end once the 2oo slots have been filled. If all slots are not filled by September 15th, the draw will take place with the available entries.
May i add that In my opinion these are some of the best designed sites i’ve seen so it should have a good convertion rate.

Thanks for featuring the site Grab4Free, and thanks for the comments on the designs, I will pass these on to the designer!