Originally Posted by dhuey
The mission: while in Florence, visit a friend in Radda for 4-6 hours on a upcoming Saturday afternoon/evening.
Renting a car may be your best option. Have you tried AutoEurope? We have a great deal for next week in Florence with them. (Avis)
Sita has a bus #7 that goes to Radda, probably right from the train station in Florence. Here is the site
http://www.sita-on-line.it/HomePage.htm
On the left, select Toscana, then select Chi Siamo, then #7 nella provincia di siena
I'll let you find the rest and translate the timetable.