Depends on how many miles you would need, it may be worthwhile to 1) cash in for a domestic award ticket (25k), 2) apply for mileage plus visa for 20k with annual fee waived for the 1st yr (which would give you 50k total), 3) get more miles by flying, or 4) participate in promotions with partners (such as the iDine one right now) to get to your target mileage.

-Uck