Helsinki
A day trip to this modern city in Finland is really worth the effort. It's located 80 kilometers from Tallinn (1,5 hour with the fast ferry) and it's great for a day's shopping and some browsing. Drinking alcohol is one thing you better do in Estonia. For the rest of it, prices are not that bad!

Riga
The capitol of Latvia, Riga, is called the Paris of the north. This city is bigger than Tallinn and has beside many shops and restaurants also many beautiful buildings. The city was completely renovated and is definitely worth the effort visiting. It's about a 5-hour drive from Tallinn.

Saint Petersburg
Saint Petersburg is the summer capitol of Russia and mostly known for the Hermitage. In 2003 the city was completely renovated. You can get there by ferry from Tallinn, but there are also several buses a day going there. The only thing is that you need a visa for Russia and this is expensive and rather hard to obtain. But especially for the people who are staying a bit longer this trip is still a recommendation.

Stockholm
The capitol of Sweden is very modern, but it has a very small and old center. You can get to Stockholm from Tallinn by night boat, then check out the city for the whole day and then take the night boat back. On this boat there is beside cafés and restaurants also a discotheque and there's always live music and a show ballet.