what is the cheapest way to get from berlin to amsterdam?

The distance is about 650 km, so walking will take far too long.

Hitchhiking is possible, but not really safe nor reliable.

By car it should be about 7 hours, but hitchhiking it might take longer.

I think it is legal as long as you do not endanger the traffic, and hitch hiking on the motorways is often also not accepted.

Cheapest public transport is the bus, this site should help you find which one and how much it costs:

http://www.eurolines.com/index.php?id=113&L=0

(Go to the right TV mast for the bus station, friends of mine where at the wrong one, luckily they had enough time before the bus left to get to it.)

For train this site should be your best bet:

http://www.bahn.de/p/view/international/englisch/i...

In a travel guide I have they mention special price tickets from 29 Euro, but that is just a very small number. 100 Euro is more likely, but it can still be higher if you are late booking or want to travel peak time.

If it was further away I would look for flights with the cheap airlines (you might still) but mostly their cheap seats are booked out months in advance:

http://www.skyscanner.net/eur/?redirecturl=1

http://www.whichbudget.com/

Amsterdam Berlin Bus

you could try hitchhiking If it's just the Netherlands you want to go to, and it's in the weekend, the german railways have the schoenes-wochenende-ticket which is like 35 euros and you can use any train that isn't intercity or eurocity in all of germany, all day, with up to FIVE people. It can get you to Enschede, or Kleve (20 km from nijmegen), or Kaldenkirchen (walking distance from Venlo) or Herzogenrath. hth

walk.