some front and rear shocks, generally "nicer" ones have an optional lockout that you can switch. Yes, with front and rear lock out you can turn your bike into a rigid which is nice for on on the road. If you can lock out the back that's nice for a long climb.

I once rode the NORBA XC course ( for fun) with reverse suspension...front locked out, back activated. And I thought it was my riding, that I was having "one of those days"...

irulan