This logo design blogger is running an excellent example of a contest that anyone can copy and create their own variation of to promote their website. Northern Ireland logo designer David Airey is offering more than $4,000 in prizes in his version of this contest. Contest details here. (Addendum: here's a variation that is also an incredibly effective contest for getting traffic and subscribers.)
He's offering a wide variety of prizes, and giving you entries for linking and/or subscribing (feed) to his website. (I believe if you did this in the U.S., you would have to provide a way for entries to be had without requiring anything of entrants other than providing contact information of some kind.) You get extra entries for linking to prize providers.
In case you don't see how this works, by making the site and contest entry page highly visible, and offering a reward for linking to prize providers, it becomes worth it for many to be a prize provider.