If you mean locking the hub but not the transfer your still going to "crow hop" and chop the tread on the tires if not something worse. You will also be turning gears and pull mpg down as stated above.
You can lock the hubs manually and leave them that way. As long as the transfer case is in 2WD you will be OK. But you may have a slight decrease in fuel mileage, and perhaps a little more "road noise". The front wheels will have a little more rolling resistance.
I've lived in places where I locked the hubs at the first snowfall and unlocked them about the first of March. Never had a problem.
I bought a truck from a guy who did this, NOT a good plan, i had to replace the hubs and there is a inner needle bearing that supports the drive shaft (too support it as it enters the hub) and both sides where toast! pain in the butt to replace.