Laptops have built in transformers (it's the little box, or sometimes big that is attached to your power cord). This transform would be rated for 220 to 110 volts.
Just make sure you have the correct plug adapter. Italy uses this sort of adapter
but if you are in a hotel you will likely only need at continental european adapter
Again, if you are in a hotel the concierge will likely have adapters, if you have forgotten to bring one and failing that many hotels have an outlet in the bathroom for electric razors... they are always North American compliant and will accept your power cord.
The other thing you should keep in mind is phone adapters. Not all hotels have wireless or highspeed and those that do, can be expensive (if you aren't on an expense account). Some phones in your room will have a data port which will allow your RJ11 phone plug to connect but in some countries you will definately need an adapter if you are using dial up.