we are going to venice, rome and florence....one friend on our trip has roots in san marino...where is it in comparison to these 3 cities? how should we fit it into the trip?

San Marino is located within Italy; it's quite a small country, although not as small as SMOM (the Sovereign Military Order of Malta, which is about the size of the Vatican and is up on a hill overlooking Rome). If you have friends who collect postage stamps, make them happy by bringing them some from San Marino. Or from SMOM, for that matter.

San Marino is slightly north and east of Florence, almost on the Adriatic Sea.

Your friend would probably like the museum of the history of emigration from San Marino. A friend (an Italian from Milan) and I (an American of south Italian ancestry) visited this little museum together this past October when we were in San Marino. We both found it interesting even though we don't have roots in San Marino.

when you say "slightly north and east of florence"...how far is that? an hour? 2 hours? could it be a day trip?

According to viamichelin.com, San Marino is about a 2-3/4 or 3 hour drive from Florence.

La Repubblica di San Marino is a very short drive from Rimini, on the Adriatic Coast, in southern Romagna, on the border with Le Marche.

BTW, SMOM is not a "country" recognized by the United Nations, or any other prominent international organization, as far as I can tell. However, Vatican City is a recognized sovereign country, and is quite smaller than San Marino.

I believe that SMOM is recognized by the Vatican, but that's about it.

Years ago I read an interesting little book about all the very small countries, including San Marino and SMOM. We went to see SMOM while in Rome, primarily to look through the keyhold that gives a great view out across the city. The church at SMOM is interesting as well.