About an hour from Spello by car, and well worth the drive.
The drive to Spoletto is quite scenic in and of itself, plus when you arrive you'll be treated to a lovely town with spectacular scenery behind the city. Umbria's jewel.
Check out my VT page on Spoleto.
Assisi is gorgeous and not to be missed. Only 20-30 minutes from Spello Stay away from Assisi on religious holidays and weekends due to the hordes of tourists.
Please check out my Assisi page for more tips and photos.
The food in Assisi is rather good. Look for wonderful pizza and rum raisen cheesecake. Yummy!
I did not get here on my trip, but I wish I had. About an hour by car from Spello. It's another very historic and beautiful town. Next time I'm in Umbria I will not miss Gubbio.