I know that diamond chainsaw is suggested many times before, and Silk Touch tools too, but maybe this idea will be somewhat useful.
Basically: you may already seen like different peoples (masters) can use chainsaw to make a sculptures from ice and different other things. So we can have a diamond chainsaw that is just slightly better than a regular one, but it will gain Silk Touch when you have enough experience level (30 for example (configurable?)) (become a master) and will lose it if not. So when you become a "master" you can easily saw block's out of rocks.
That's all.