This is a great place to stay in Rome.
100m from the Santa Maria Maggiore and only a short walk from the Termini which is the essential starting point for anyone new to Rome - trains, tours, taxis, banks, currency exchange are all available at the Termini.
Hercules is the proprietor. He is a Roman and obviously loves his city. On arrival he presents you with a map of Rome and gives invaluable advice as to the best places to go and the best way to get there.
If you can't find it, and it does have an identity crisis, just ring Hercules and he will appear to make you very welcome.
The three flights of stairs are a bit daunting, but from our experience, more the norm than the exception in European accommodation and Hercules and his partner are more than willing to help you lug your luggage.
The Blue Hostel made our stay in Rome all that much more pleasant because of it's comfort and convenience.

The Blue Hostel is THE place to stay in Rome. My girlfriend spent some days there with her friends and she was amazed not only with hostel itself but also with the service quality. Ercole is a great person and will be surely your point of reference in Rome. He was not only nice with them, but also he made me a huge favour to me, I have no words but only grattitude for his kind help. I encourage anyone who is travelling to Rome to stay in the Blue Hostel, I promise that you will have a great time!

I don't feel that I have much to add to the glowing comments by other travellers below. The location, the accommodation, the excellent value - and a host extraordinaire. This is definitely a home-away-from-home. Thank you to Ercole for helping to make our time in Roma such a memorable experience.

It's long time I don't live in Rome anymore, but I happen to visit the city often...this time I stayed for several days at Blue hostel. Great value for money, perfect location in central Rome with homey and warm housekeeping by the owner Lello. Location is really central for visiting the classics of Rome. Rooms are furnitured with an artistic mix of tradition and modernity. The sensation while staying in the room is that everything is looked after (I also suspect that some of the pictures are directly made by Lello...uh!) and that Lello really cares about his guests being always at disposal, kind and really informed about what's going on in the city (clubs, feasts, museums). Next time I will spend at least one night in Rome? No doubt...I'll stay at Lello's Blue Hostel!