DO call ahead for reservations at this popular place. I didn't stay here when I first arrived in Athens, because they quoted me 100 euros for a dorm bed during the Para-lympics! I called ahead from Mykonos in October and got my dorm bed for a more respectable 20 euros. This place was packed, and I saw families being turned away after I had checked in.
Student & Travellers' Inn is ideally located in Plaka, close to shopping, restaurants, bars, and views of the Acropolis lit up at night. It was really easy to meet new friends here -- just sit in the shady courtyard and strike up a conversation. Hang out until you find some people to go out with, and you'll have a great time. My new friends and I walked around the base of the Acropolis at dusk, enjoying people-watching. After dinner, we made our way back to the hostel and decided we weren't ready for bed. We stayed out late at a bar on the corner, near the hostel, enjoying the wine and the company.
At Student & Travellers' Inn, you will enjoy the neighborhood and the atmosphere and make new friends easily.