I found a couple sets of the toy "Cube World" at Zellers the other day - it's a bit silly, but fun to watch the characters interact with each other. There are magnets on all sides of each device, which allows the "stick men" to move from one cube to the next. Here's a pic to get a better idea of what Cube World is. Not as interactive as a Tamagotchi, but definitely entertaining to watch. I think I'll leave it on my work desk to show my colleagues when they stop by.
