Great thread!!
This is in response to an old post but I have to say

about Goofy and Belle giving massages in the room. It's a funny image first of all, it's also funny that the husband would have gotten Belle and the wife would have gotten Goofy - maybe that's her type?

Anyway, for those with deep pockets out there, I do believe you can arrange for some kind of character interaction. An example would be that Mickey and Minnie attended our wedding reception at the Living Seas Lounge for 30 minutes. They danced with us and our guests and posed for plenty of pictures (no massages though!!). The cost... currently running $1200 per HALF HOUR for the two characters. (I believe in the neighborhood of $800 for one character for the same amount of time.) As some people say, anything is possible at Disney if you have enough money.
A couple of free ideas we have:
1) We have gotten lucky a couple of times and come across a ton of characters at the "teardrop" area in the Magic Kingdom. It's an area by the train station in Toontown. It's kind of hidden but if you are riding the train, you pass by it right before the train stops in Toontown. (I think it might be a smoking area?) Anyway, we think they might be doing some kind of market research or something because what appear to be cast members in business casual clothing escorting the characters out and take pictures. Last time we found it there was a cast member videotaping. You can really get a ton of pictures with all kinds of characters, some of which are rare, with little to no wait (unless, of course, the train has just let out!) Some examples of characters we have gotten are: Pinocchio and Gepetto, Darkwing Duck and Launchpad, the three mice from Cinderella, Friar Tuck, Rafiki, Dopey, and several others. You can't ask about it at guest services b/c it's supposedly "unscheduled" but we came across it around 2. If you're in Toontown, doesn't hurt to stop by.
2) Not sure if they still do this but they used to have a hoedown featuring Brer Rabbit (my favorite in case you can't tell from my avatar!!!!) and the Country Bears where they do the hokey pokey, and some other things. While I will take any chance just to see my fave in "person", last time we came across this we got to participate (thank you wedding ears!!!) I got to square dance with Brer Rabbit! I think this occurred between 4:30 and 5 in the stretch of Frontierland where the parade first comes out. Fun to watch, even more fun to participate.
3) Someone else mentioned the talking trash can at Epcot. We have seen this in Tomorrowland as well as the area in Rafiki's Planet Watch outside the Affection Section at AK. If you look closely at the people seated nearby, you can spot the person controlling it!