Accommodation
Hostels
There is a large number of backpackers passing through Krakow, and a large number of travellers also decide to take advantage of low Polish prices to hang around and learn Polish for a month or so. Between them they are able to support a whole range of hostels which open year round offering accomodation for around the 40 zloty mark (slightly more in summer). Dizzy Daisy run three year-round hostels in Krakow, the best of which is the one on Pedzichow (the reviews of Dizzy Daisy hostels on some hostel sites are quite strange incidentally because they have been attached to the wrong hostel). Otherwise the quality is quite variable. Two of the hostels with a good reputation are Mama's Hostel and Nathans Villa. The less highly-rated hostels have very few visitors in winter, and are therefore a less good option for meeting people. It may be a good idea to stick to the hostels nearest to the train station, as they are easier to reach with your luggage and attract the largest crowds.
It is possible to get cheaper accomodation at the Polskie Towarzystwo Schronisk Mlodziezowych (Polish Youth Hostel Association) affiliated hostels. Reviews suggest that these are a guarantee of inconvenience however, with lockouts, curfews and a total lack of atmosphere. Krakow is probably a good place to take advantage of friendly accomodation and meet some people.
Couch surfing
Like Warsaw and Prague, there are quite a lot of ex-pat British and Americans living in Krakow, less because it has large multinationals based there than because it is a good cheap place for freelancers such as writers and translators to spend their time. Many of these people are extemely enthusiastic about their adopted town and are keen to welcome visitors and show them around.