2
The cheapest option will be by bus.Try Berlin Linien Bus....from around 20 euros.About 3 hours each way though...a pretty long day trip!
5
Like Luca, I doubt a tour would work out cheaper. When will you be travelling? Have you already checked fares at http://www.bahn.co.uk (German Railways) or did you find the ticket prices on a site like RailEurope (a broker which usually charges much more than the national railway companies)?As a sidenote, I spent 2 days in Hamburg earlier this year and was slightly underwhelmed, to be honest; it's nice city when you're in the area (and obviously I don't consider Berlin "in the area") and have some time to spare, but not very special if you ask me - perhaps it's just me, but apart from the area around the town hall Hamburg's city center is just as unattractive as any big German city that was bombed in WWII, the port is perhaps impressive if you're into big ports and haven't been to Rotterdam yet, and the "world-famous" Reeperbahn pales in comparison with Amsterdam's Red Light District - both are overrated, but at least the latter's saving grace is that it's architecturally interesting.
It is definitely a lively and bustling city (I stayed in the colourful area immediately east of Hamburg Hauptbahnhof, at least that was genuinely dirty and seedy - move on though if you can't stand the smell of kebab), but I am not sure if it's worth going out of your way for.
6
You could try to hitchhike from Berlin to Hamburg. Hitching is fairly easy in Germany as the road network is excellent and people are generally very hospitable. I've hitched many times in and through the country and never had any problems. Check Hitchwiki for some tips on hitchhiking and good starting points in both Berlin and Hamburg.However, I have to agree with Aribo. Hamburg isn't that impressive. There is enough to do in (the east) of Berlin to completely fill up a week. Or several.
Edited by: ostkreuz
