These are sites that I found helped me when making my decision and planning my trip.
For inspiration:
www.geekeasy.com - this guy hit the road and stayed there for years. it hasn't been updated recently, but his stories really peaked my interest.
www.bradcoffman.com - Brad spent a few months in Europe for a documentary as recently as this summer.
www.ricksteves.com - ALL HAIL RICK STEVES!
For planning:
www.onebag.com - Onebag's mission is to get travellers comfortable with bringing only what they can carry.
blog.inyourpocket.com - great little travel site, specializing in eastern europe.
www.hostelworld.com - very useful site for booking rooms.
thorntree.lonelyplanet.com - when all else fails, ask a fellow traveller!
www.kayak.com - i purchased my ticket one month before leaving. Every other site told me this would cost me at least $1500. Kayak found me a discounter selling the same tickets for half the price.
