Do you mean on-line real-time web-cams like. This one of Krakow?
If so just google "online webcam Krakow, Katowice and Wroclaw.", that's what I just did with Krakow.
I tried "Kamera online" instead and got the one for Katowice. Here it is, I got it from this site (Kamera.pl)
It looks like they do webcams all over Poland.
Something very cool is if you scroll down on that Kamera.pl page you get to stand in Broadway in NewYork and look all around, it is really cool, even if it is not what you are looking for.
One more thing is WikiMapia Poland, it is not a webcam but you click on various parts of the map and you can see photos that were taken of that place. And there is also google map of course.