From Finland, consider taking the ferry across to Tallinn, and from there exploring the Baltic Sea countries (Estonia, Latvia, Lithuania). Much cheaper than Scandinavia, with some similar customs and many quite unique. You can take the boat back to Sweden from Helsinki, as well. Or you can fly cheaply (I think 49 Euros) to Copenhagen, Stockholm or Oslo. Might be more in the summer, of course. We won't be home much through July and August, but if you decide to go to Vilnius, I could give you zillions of pointers - and we'll actually be doing our travel through the area at the same time, so could potentially meet up. If you see a family consisting of four children aged 1 - 8, a laid back dad and a frazzled looking mum, that would be us!
Check out www.inyourpocket.com
for lots of tips and detailed info on lots of cities, mostly in Eastern Europe.