By Train Travel

Rail Europe - You can get unlimited travel in Europe or you Can get a "Germany and Benelux Pass" that allows you up to 10 unlimited days travel in two months. This one costs $374 (£207 ish)
You can get a one month pass for $ 946 (£525 ish) but there are many other cheaper options on the Rail Europe site.
Eurostar - Get a connection from either Brussels, Paris or Lille.