I've been thinking of making a half-truncated 3x3, but instead of normal caps, add something like lego onto the cut sides, making what I would call a rubiks hybrid. I would have to cut the lego so as it would fit on top on the sides, but if i did this right, I think it would be a pretty neat mod. The turning would most likely bee not as good as the original cube as the lego sides might catch on each other, but I think it's worth a shot. Will post some pictures if I end up making one.