Someone Loves Photoshop
Photo Credit 1
As it really is just a quick walk from the Trevi, you can either wander through some more quaint and winding streets:
Quaint and Winding
Or, just hop back on the subway. Either way. Notice the awesomely apropos name of the station.
Again, as is a common theme in Rome, you will fight through some crowds to take a picture of something that has survived for a certain amount of years. Honestly, after taking the time to look at the steps and marvel in their majesty, the better course of action is to check out the alleyways. The coolest things in a city can be found in the alleyways just a stones throw away from the tourist districts. Of course you should always use common sense, and by no means do this at night.
Rome is quite a different city at night, parts of it are amazingly friendly and set up to support a thriving night life, and other parts turn into areas where Gypsies attempt to either rob you or sell you various items are prices that might as well be robbery. It is amazing how fast a train station can go from deserted to a newspaper and rubbish filled bazaar, then back to deserted again. I am sure there is some transient puppet-master at work, attempting to stay just one or two steps ahead of the police.
Photo Credit 1: http://images.nationalgeographic.com/wpf/media-live/photos/000/621/cache/spanish-steps-italy_62118_990x742.jpg