I have to be upfront: I did not expect a tumbleweed to be one of the most exciting design concepts I'd encounter this year. Tumbleweeds, in the cultural imagination, belong to Westerns and dusty ghost towns. They're the kind of thing that drifts across an empty street right before a showdown, the universal shorthand for I have to be upfront: I did not expect a tumbleweed to be one of the most exciting design concepts I’d encounter this year. Tumbleweeds, in the cultural imagination, belong to Westerns and dusty ghost towns. They’re the kind of thing that drifts acro... [3927 chars]