Let's see...
It's where King Erik "the Saint" IX of Sweden was beheaded and allegedly where the head rolled a spring sprang up.
Carl von Linné studied here and became the rector. He's also buried at the cathedral.
Our cathedral is the biggest cathedral in Scandinavia.
We've also got the second oldest anatomical theatre in the world.
Both Olof Rudbecks were professors at the university here.
Anders Celsius was born here and was a professor at the university.
Dag Hammarskjöld (
wiki) grew up and was buried here.
Ingmar Bergman was born here.
Pope John Paul II visited here 1989. (He kissed my cheek.)
Veronica Maggio came from here.
Carl M. Bellman (
wiki) also studied here, but he's not much known outside of Sweden I don't think.
There is a ton of other claims to fame for my town but I can't be arsed to remember them all =P
EDIT: Oh and it's also the home-town of Peter No-Tail =D