|Boxed Burr - Solved|
At first glance Boxed Burr looks more like a puzzle box than a burr, and it takes a bit of a strange rotation move to actually remove the first piece (you can see the locking piece one the second picture).
Once the first move is discovered and a piece is removed it becomes much more obvious what kind of puzzle this really is.
It turns out that inside is a standard six-piece burr, but one end of each burr piece is attached to a panel, each of which make up the box shape once they have been correctly assembled. I think it actually looks at it's best with just the first piece removed. The first (locking) piece rotates slightly against its panel, and that allows you to twist it in order to lock it in against the other pieces. I really like puzzles that have the ability to solidly hold themselves in their solved position.
The burr puzzle itself isn't particularly difficult, but having the panels on the pieces makes it a little bit more of a challenge, although not significantly. It shouldn't take an accomplished puzzler too long to find the solution, and I'd even wager that most new puzzlers would be able to solve it with a bit of effort as well.
Although Boxed Burr isn't very difficult to solve it is well worth having just for how fun it is. Plus I think the design is incredibly innovative and aesthetically pleasing as well.
This puzzle came directly from Tom, and that would probably be the best place to start if you were wanting to add one of these to your own collection. Failing that, puzzle auctions are your friends.