I couchsurfed both nights in Krakow with three lovely hosts: Gosia, Gosia, and Bartok. They have couchsurfers pretty much every night of the week, and while I was there they were hosting not on me, but an Australian, another American, and two Polish girls. They host so often that you can see all of their supplies on the shelves here: extra sleeping pads, travel books, hitch-hiking signs, and plent of signs in English to help you find anything you want all around the house (drawers marked "silverware" or "cups", etc.).
The name of the street eludes me at the moment, but it is a major shopping street connecting the Main Square to the gate at the edge of Old Town (Stare Miasto in Polish).
This is one of the Gosia's and Bartok singing some Polish folk songs for me and the other cs'ers. I played some music for them as well, and if you are my friend on facebook you can watch a video of Gosia singing Bob Dylan's "Tomorrow Is A Long Time" in Polish!
The same street pictured above, this time in daylight with St. Mary's Basilica in the background. St. Mary's is the main cathedral in Krakow, at least in terms of tourism, size, and prominence. There are MANY churches in Krakow (a whole lotta Catholics).
This is the Main Square in Old Town, a very large, beautiful space to spend some time eating food and drinking beer. A friend of my hosts told me that it is the 2nd largest Main Square in all of Europe, though I haven't confirmed that, so don't quote me on it.