what can I do with a 3x3x7 shape mod?

Are we talking a proportional 3x3x7 or a 3x3x7 cube? I'm not familiar with the mechanism of 3x3x7s in general, but if you're talking about the cube version it may be possible to do just about any shape mods that you could normally do on a regular 3x3x3. I would recommend only shape modes that require cuts though, because it may be just a tad too difficult to build up on the thin slices (but it's probably possible). With that in mind, I would like to see something as simple as a barrel to see how the slight jumbling of the barrel affects the thin slices.