In reply to benpatterson: Loads of places on Finland on the lake systems - the lakes are huge, but very complex in terms of islands and peninsulas everywhere so you don't need to do any major open water crossing if you don't want to. Normally you can be pretty close to the shore line. You can camp anywhere that's not someone's garden and in the many places you'll find organised, free camping spots where there will be a fireplace (normally wood for it is there too) and wooden lean-to shelter for those who don't have tents. This video
http://www.visitfinland.com/article/a-days-kayaking-on-lake-saimaa/ gives you a very fair view of what the east finland lakes are like. This site
http://www.wildcanoe.com/en/enwildcanoe.html suggests some routes, 1 to 10 days. Lots of places will rent you the kayaks and even all the camping gear too if you don't have your own. Ignore the alpkit review, but all the pictures in this blog post:
http://lightfromthenorth.blogspot.fi/2012/06/alpkit-in-operation-kayak-tour... was from a three day tour I did last summer starting about an hour's drive from Helsinki, but I'd got to the East of the country as there's more space and more tourist infrastructure to suit what you're looking for. This summer's weather was a bit crappy but better than England's still it seems. Last summer was super hot and sunny. Generally I would say the Finnish summer is better and more reliable than the UK's but of course you could be lucky or unlucky there.
