Maridalsveien 303 formerly ‘Hasleveien 8’. I have not been to the new place in Maridalsveien where Ragnar & Froge moved this January. But I guess they make it as nice as their old place. It's still the cheapest place to get your own room in Oslo. Single room 250 NOK, double room 400 NOK. Linen and towels included. Tel: +47-90013661 or +47-95217847
Haraldsheim The classical HI hostel, I guess everybody already stayed there. It's quite far out of the center. Dorm from 235 NOK, single room from 395 NOK, double-room from 520 NOK. Linen 50 NOK, Towel 20 NOK. Prices incl. breakfast; 15% discount for HI members. Haraldsheimvn 4, Tel.: +47-22222965, online booking.
Anker Hostel Dorm bed from 200 NOK, double-room from 525 NOK, bed-linen 50 NOK, towel 20 NOK, breakfast 85 NOK. Storgata 55, Tel.: +47-22997210, online booking.