Now having said that, narrower + higher pressure WILL get you less rolling resistance, BUT, and this is a BIG "but," they'll also get you:

1. more flats
2. more chance of rim damage
3. more chance of broken spokes
4. more critical tire pressures

I, personally, prefer fatter tires at lower pressure. I've never had a flat, never had rim damage or broken spokes, and a simple thumb-test of tire pressure prior to a ride is always sufficient.

You pays your money, you takes your choice...