I visited Rome in the Summer of 2000. That was well before becoming Catholic in 2007. I tell people often that most of the trip was spent staring at ceilings in churches and palaces. Of course we went to the Vatican.
One of the traditions is to touch the foot of the statue of St. Peter (seated on his throne). I recall seeing just how rubbed down it was. You can't even really tell its a foot anymore and it is incredibly smooth to the touch. When I think about it I can still feel it on my hand as if it was yesterday. That's what several hundred years of pilgrims touching a statue will get you. I have no idea why that has stuck with me.
Going to Rome (and France, England, Italy, Scotland, Germany, Austria, Spain, Switzerland) and seeing the glory of the Catholic Church was probably one of the real catalysts for becoming a Catholic. Viewing those things had an effect on me which I don't give as much credit as I probably should. Pretty stuff is not enough to make a guy convert, but a witness of faith over 2000 years is a pretty good place to start.
Happy feast of the Chair of St. Peter in Rome everyone.