I had a very pleasant stay at Patrizia's house. Nice, big enough room, bathroom and a littel balcony. Little sweet snack or yoghurt and a coffee for breakfast are provided. You get a key upon arrival and are able to come and leave as you wish. The house is in easy walking distance from Piazza del Popolo - although, if it's late and you are tired with sore feet consider taking the tram, especially when you've got a valid ticket anyway. Might prove a wise decision ;)
It's easy to find: After leaving Piazza del Popolo just walk straight ahead and at her street turn left. Tram stops almost right at her street.
I'd stay there again any time. Thanks.