ArchitecTour
Personalized tours of the Eternal City in the company of a Roman architectural historian.
http://www.architectour.com/

Chris Nyborg
Notes on the history and architecture of dozens of churches, chapels and oratories in Rome.
http://roma.katolsk.no/alphalist.htm

Great Buildings.com
Pictures of major monuments and buildings in the capital.
http://www.greatbuildings.com/places/rome.html

Roman Odyssey
Provides guided tours of the city's architectural and artistic treasures.
http://www.romanodyssey.com/

Rome - The Eternal City
Lots of pictures of ancient Roman monuments in the city.
http://sights.seindal.dk/sight/2_Rome.html