There's a sheerly fantastic post on the EuroCheapo blog today on how to nab cheap European train fares. Written by Nicky Gardner and Susanne Kries of hidden europe, the post is indispensable for budget-oriented travelers who don't want to be fleeced. Gardner and Kries come up with one dramatically-illustrated general suggestion: book your train journeys on the DeutscheBahn site. The post compares fares offered through UK and US agencies to those offered on the DB site, and finds that the latter offers much less pricey fares.
The DB site is also good for constructing fantasy train journeys. Just saying.