I have a 2000 Dodge Intrepid R/T, 3.5 w/auto stick. I run Valvoline full synthetic 10w-30. It will usually use about 1/2 qt. between oil changes (5000 mi) but it seems to be using a little more than usual now. It has 106,000 on it. I was thinking about going with a high mileage oil or is that stuff just a gimmick? Maybe go back to conventional? What do you guys think?

A half quart per 5k is sure not excessive in my book. However, if you feel the need to try a HM oil, Maxlife is excellent. They have both a syn blend (group II/III) and a syn (group III) version.

106,000 miles on a 3.5L, it should still be in great shape. Normal maintance at that mileage is a new timing belt and water pump. I did mine at 120,000 miles and the belt still looked good, but I'd rather error on the safe side.
I would not worry about using a high mileage oil, but I don't think it would hurt either.

Roller camshaft engines are not high mileage at 110k miles. I would stick with the synth oil and do the required maint. Use a good upper end treatment in your fuel every once in a while and keep driving.

Thanks for the replies. The water pump and timing belt were already replaced at about 98K. I'll just stick with what has been working.