(This is a serious question in need of a serious answer.)

The two main "police forces" are the carabinieri and the polizia.

Both have the job of your typical police force, and inevitably they end up stepping on each other toes. The reason 2 different forces were created, I believe, was to avoid a coup d'etat. In fact, when a coup was attempted in the end of the 60s, they used the Italian park rangers (guardia forestale), but that's another story.

In addition to carabinieri and polizia, there is the Guardia di Finanza, whose main job is to go after people who commit financial frauds -- and if they're lucky they'll end up getting a job w/ Berlusconi and Guardia Forestale (park rangers).

Police, military police ("carabinieri") and police for tax crimes and other financial crimes against the state ("guardia di finanza"). The reason to have police and a separate military police is to be search in post ww2 desire to avoid another dictatorship.

The efficiency of such an arrangement can definitely be questioned, but honestly so can the British arrangement of having separate police corps in different counties not even sharing the same data on a common and decent IT system.

well, we have quite a few boys in blue here!

Carabinieri are the very professional guys - semi-military, who will also respond to traffic incidents if you ask them nicely. The 'dreaded' Guardia di Finanza have arrested me for buying a bottle of water without getting a VAT receipt, and trying to arrest me for having had a haircut for the same motive.

I fought the law and I won!

The Polstrada look cool and have a nice webpage where you can check-out their cruisers http://digilander.libero.it/autopolizia/page30.html

The Polizia del Stato State Police are mostly in evidence at the Italian Borders - though I have been called in for questioning about that dodgy document I accidentally signed 8 years ago.....

The Polizia Penitenziaria seem to run the prisons, Corpo Forestale seem to drive around in Green Landrovers a lot

"The Keystone Kops" of Italy are possibly the various groups of Polizia Proviniciale, Polizia Locale, Polizia Communale, Polizia Municipale, Vigili Urbani; rumour has it that they like uniforms and guns but were disqualified from joining one of the *real* forces, so they end up regularly extracting €50 fines from Motorists? (A vigili did shoot someone a couple of years ago in Milan, near La Scala, for a traffic infringement. They can have my €50 anytime!)

I'm sure there are other groups, some subsets worthy of a mention are the special "Hospital Attack Squad" of the Carabinieri , I believe, who - mostly in the Summer, swoop on an unsuspecting Ospedale and lock all the doors and start counting Doctors and Nurses and State Employees - to determine who is 'on duty' and 'at the beach' or possibly both!

Then there are just the unmarked cars that drive around with a flashing light on top, who are they? maybe SISMI going to arrest the other-half of SISMI or could it be my neighbour, Umberto Bossi's escort?

There are many opportunities to meet the nice Italian Police, armed checkpoints are quite common, where your car documents are controlled at machinegun-point, though nowadays many automatic radar "autovelox" are leading to database policing. Watch those speedlimits on the SuperStrada!

The park rangers did not fail in their uprising - they effectively took each and every national park HQ building over all the national forests - only nobody ever knew about it so the rangers went back home after their rations ran out.