One free day and free city guide with Eurail Passes at International Rail
And if you pay over $500 for your pass you get a Lonely Planet City Guide free (valued $25)
"Eurail is offering an extra travel day for free to everyone buying a Eurail Select Pass for 6, 8 or 10 travel days (the 5-day and the 15-day Eurail Select Pass are not included in this special offer). This means if you buy a Eurail Select Pass for 6 days within 2 months, you will receive a Eurail Select Pass for 7 days within 2 months and so on.
All country combinations and all categories of Eurail Select Pass (adult, saver and youth) are included in this offer.This special offer is valid for all purchases made between February 1, 2007 up to and including March 31, 2007. Travel must occur within 6 months of purchase"
I quickly checked the prices of the Eurail passes thru International rail and they appear to be about $40 cheaper than other sites and then you also get cashback
Your Eurail Pass also comes with other freebies - read when you click thru the link