NGI2008 in Krakow

I've recently been to Krakow to give a talk about some of our research and development at the NGI2008 conference. The conference was hosted by AGH University of Science and Technology which is a pretty large institution, having multiple campuses within Krakow.
After the conference, we've met in the city to do some sightseeing. What I've really liked in Krakow, was public transportation, which is cheap and pretty convenient.

It is also pretty easy to get around with a bicyle in town, though I had no chance to try it :(
A piece of polish technology:

 The famous building on Market Square:

Krakow Castle:

The conference banquet:

Guess why was everyone so happy?