I ride a '78 Raleigh Pro as a fixed and use a 44/16 here in SoCal. With 165mm cranks and 700x25c Contis, it comes out to about a 72.5" gear. I stick to mostly flat to rolling stuff here and it works great for me. Nice on the flats near my normal cadence that stiffens up a bit on the false flats for a good winter workout. An alternative would be a 42/16 for a bit more spin since I bog down a bit at times after all the holiday eating.
A trick from the trackies is to fine tune your gearing with tire size. I'm sure this is much less of a help on the road due to the variety of terrain, but it might work for you.
For those of you in SoCal, I've used it on Chuck's rides with no problems, so that will give you an idea of what works with a 44/16. I do stand a bit near the top on the last climb, but mostly to keep from bogging down (and to hang with the geared folks).