Chiado (Old Town):
Lisbon Old Town Hostel: Rua do Ataíde, 26A (5 minutes from Bairro Alto. Metro: Baixa/Chiado or Caiso do Sobre). A new hostel, opened in 2007, catering to the young hip crowd with event listings on their website, free computer and internet access in the lobby and WiFi through out the hostel. 15?-22?.

Shiado Hostel: Rua Anchieta 5 - 3º - 1200-023 Lisboa (2 mins walking from Baixa-Chiado Metro station). checkin: 14; checkout: 12. Located in the Chiado area, the very heart of Lisbon, a charming and relaxing hostel. Opened in march 2009 13?-30?.

Poets Hostel: Rua Nova da Trindade, 2 - 5º - 1200 Lisboa (30 seconds walk from Baixa-Chiado Metro station). checkin: 14; checkout: 11. The building is just next the Chiado exit of the Baixa-Chiado metro station. Very helpful staff, clean rooms, dinners and activities are organized by the hostel. Big common room with TV and free internet. Dorms and privtes available.

Hotel Borges: Rua Garret, 108. Clean, spacious rooms with satellite TV. Rooms starting at ?84.

Alfama (Old Town):
Sé Guesthouse: Rua de Sao Joao da Praca, 97 - 1100-519 Lisboa. checkin: 14:00; checkout: 12:00. This 5 room guesthouse is a charming and affordable Alfama option, with a picturesque location, fantastic river views, and eclectic décor. Some rooms are bathrooms en suite, while others share the two, clean hall bathrooms. $49 - $87.  edit

Bairro Alto (Old Town):
Bed&Breakfast Lisboa: Travessa do Alcaide, nº7 (atached at Adamastor). Good rooms in a very central bed-and-breakfast with views all over Lisbon and the river. 30? - ?40.
Camões: Travessa do Poço da Cidade 38 1E. Basic, clean and affordable. Single ?20, Triple ?60.
Oasis Backpackers' Mansion: Rua de Santa Catarina 24. Backpackers rave about this hotel, often noting the friendly staff, large clean rooms, fun atmosphere and great dinners. It is a great place for a budget traveler to meet up with other travelers and feel safe when they go to bed at night - if they go to bed.

Graca:
Johnies Place Hostel: Calcada da Graca no.18F (Right next to Graca's Belveder). Cosy hostel. No extra costs for internet, printing, breakfast. Dorms starting at ?14.