I'd like an AlphaDog. I don't know what I'd do with one but it looks mighty awesome. 400lbs is about 6-10 fully loaded rucksacks so depending on what you're up to it could be very useful. In the long term I can see something like this being used for Arctic expeditions or for mountain rescue... and taking snowboarders to the tops of big hills!

Link: AlphaDog, A Four-Legged All Terrain Robot by Boston Dynamics (via Laughing Squid)