and one with info and pics on Rome's historical trams and tramlines.

http://xoomer.alice.it/vform/tramroma/index.htm

Here's a pic of one of the newer ones:

A rare photo of a Roman tram in the snow (the tram's common enough, it's the snow+Rome combination that's the real rarity!)-

and one of a real old-timer... dating back to 1911:

...

Sadly, through the years and especially in those from the 1960s through the 1980s, many of Rome's tramlines got discontinued.  The worst-hit seem to have been the longer-distance ones serving the outer suburbs and hinterland - including the Castelli hilltowns zone where I live. :-(

"Ignoring moralities is always undesirable, but doing so systematically is really worrisome." Mohammed Khatami