I almost forgot...

There is a slight chance that you might be able to do a EWR-SEA-HNL reward flight. Continental has two code-share flights from SEA-HNL with Northwest Airlines. The flights are CO 5925& 5945 SEA-HNL and CO 5924 & 5946 HNL-SEA.

Unfortunately, the CO seats on these flights are scarce. I have a hard enough time getting CO revenue tickets on these code-shares, much less a reward seat.

Good luck!