Vastervik is a large area with lots of bouldering. Not as dense as say Fontainebleau, but good quality rock.
Kjugekull and surrounding area contains some amazing granite bouldering. Kjuge itsself has a really good concentration of problems. It takes less than 30 minutes to stroll from one side to the other. This is probably the best bouldering in Sweden. Lots of topos and videos on 27 Crags. Blogs containing info and vids are skaneboulderhunter and kjugekull.
There is also bouldering around Gothenburg. Details at Göteburg Bouldering Online