If you have a high-def video camera, be sure to take it on a hike with you to the bottom of the canyon. HD is the only way to bring out the gorgeous contrast of blue sky and red rock that you'll want to show everyone at home.
Winter is an excellent time to go to Europe. There are next to no lines for the museums, you can experience the cities like the locals do and everything is cheaper! Plus, Christmas and New Year's Eve in Europe are very special.
If you are doing a time out tour (staying in hotels), a travel iron/hairdryer will come in handy as many european hotels do not provide these facilities.