If you don't mind ugly spots, Sthlm is the place to go =)
However, you can take the boat to Gotland, it's only a few hours aways. Mauricio Abreu (spelling correct?) went there recently and loved the place, according to a local newspaper. Very nice flatwater spots as well as wave spots.
Snowkiting is a bit more difficult to find as it doesn't snow that often near the coast but sometimes it does. However, you can go by train or car to SÃ¤len and Ã…re to get some really nice snowkiting.
Check out the winter spots at http://spotguide.kicks-ass.net/vinter/default.asp
Oh, and you can always go to the west coast to experience sweden's finest spots =)
I found this -very- old post with the search engine.
I'm french and I may go working at Stockholm.
I wonder if there are kite beaches nearby. The situation may has changed since 2002.
I'm used to kite from very tiny beaches, so I don't mind if the spot is awful.
And what about snowkiting nearby?