[youtube]http://www.youtube.com/watch?v=pThb0LKbHsU[/youtube]

Probably not useful because people will just want to play with it

Here is a very cool design for taking a small round table and turning it into a large round table. Very ingenious, and very slick. More videos after the jump.

[youtube]http://www.youtube.com/watch?v=ci1pK5K9C64[/youtube]

Cool design, but the pieces below end up being knee-bangers

 

 

[youtube]http://www.youtube.com/watch?v=BSMYj60ZgT8[/youtube]

Also very ingenious