To break up the monotony of the rollers/DVD routine, I'm putting some washers on each side of my powertap hub to space it out to 135, and slapping on a 9 speed cassette. Taking the MTB out into the snow for some 10mph, no rear brake needed, 300w SST goodness.
And also doing 15s on/offs until I puke.
The way I figure, winter is the only time I don't have to worry about being too tired from killing myself on the weekdays to perform well on the weekends. If I'm tired, instead of doing poorly in a race I just go for an easy 2hrs in the woods or watch "Wedding Crashers" on my rollers. No big deal.