I'm sure many of you already know about this so I apologize in advance if this is old news that has been posted a gazillion times. But I just discovered it and I suspect I'm not the only doofus who hadn't figured it out yet. So I thought I'd share it here with instructions for those not familiar with Google maps.
In Google Maps (http://maps.google.com) you can zoom in to a resort until its trails show up on the map. Google doesn't show trails for some of the smaller resorts, but most of the bigger resorts have them. Once you see the trails, grab the little yellow "Street View" guy in the bottom-right corner, and drag him over the trail map. You'll see some extra blue lines pop into existence which represent the trails (and roads) that Google has photographed. Drop the little yellow man onto whatever trail you want to explore and the map will zoom into a full size photo. There you can pan around by clicking the screen and dragging. You'll see a little arrow in front of your hand-pointer and if you click there the view will proceed up/down the trail. So you can "virtually" ski any trail from top to bottom that Google has photographed.
A very cool way to waste time!!