I have one of these:
http://www.performancebike.com/shop/...tegory_ID=4122
I have used a wood block in the past, but I like this gadget because it cradles the front wheel and feels a lot more stable. Has three levels of incline for whatever reason. On sale too! Only $13.
Went to the store yesterday and looked at the new Trek Madone line-up. Great machines. I'd like the SSL model (what Lance's teammates ride; he's on a newer model, the ponte verde or something), but the 5.9 is probably the most I could afford. Maybe a 5.2SL. Must give them a test ride though.