I was just in that neighborhood in January of this year, day tripping from Perugia. We stopped in both Spello and Assisi. The train trip between the two is only about 15 minutes. The walk from the Spello train station to the bottom gate of the walled old town is an easy 10" stroll. The lunch we had at the restaurant Il Pinturicchio in Spello was one of the best meals of our two-week trip (and very reasonably priced!) Do call ahead - even if it's just couple of hours ahead - for a reservation. When you arrive in Assisi, you'll likely want to take a taxi from the train station (which is "down on the plain") up to the walled city. To get back to the train station, without luggage, you could take either a taxi, or a shuttle bus. The buses are easily found in Piazza Unita d'Italia, down at the "bottom" of the old town, below the Basilica. Buy your ticket from the tobacco/souvenir shop in the Piazza.