To popcornbird:
-No unfortunately it's nearly impossible to potty-train ducks, as they don't have bowel glands to "hold it". You can teach them, but they'll always have accidents.
-Nope, no cage, but he does have a very large playpen for when we're gone. Actually cages can cause foot injuries to ducks, so they shouldn't be used.
-Yep, he LIVES indoors. We have a nice big backyard and are trying ot get him to like it (i'd like to play with the hose with him & pull out the kiddie pool for him out there) but he doesn't like it. What duck would when you can have air conditioning and warm baths? Be he does swim in our bathtub when he wants to swim; we make it nice and warm, and its big to him since he's just a little mallard, not a big Pekin or anything.

To BCBlondie:
Yep they are messy, but most of the mess is contained since he has a diaper, and we have a lot of tile. But that still leaves a lot of cleaning for me! But it is worth it, he's the greatest pet I've ever owned!