Since there were a few people who asked about the wavy lines on the sides of the box I made for the 2011 swap, I figured I'd share how I did it...
Cut a wavy line in a 3/4" cherry board. I used a bandsaw and oscillating spindle sander to clean up the cuts and get the two pieces to fit with no gaps.
Soak some 1/16" thick x 3/4" strips of contrasting wood in hot water for a couple hours to soften them.
Clamp the soaked wood tightly - with no glue on any surfaces -between the two halves of the board. Let that sit a day or two until the wood's dry. This gets the curves started in the accent strips, although there will be some springback when it comes out of the clamps. It'll look something like this when you take it out of the clamps. (BTW, these pics are from a box I made a few years ago):
Next, glue it all up (I like using plastic resin glue like DAP Weldwood) and let it dry in the clamps for a day or so. After that, I plane the board flat again, then resaw it into two bookmatched boards that end up about 1/4" or so thick after planing.
From that point on, it's just a matter of building a simple mitered box. With some care and planning on the miter cuts, you can get the accent line to line up from one side to another. The miters have to be cut so that no wood is removed from the outside face of the board. If not, the lines won't be aligned.
On this box, I got two of the four corners lined up. The other two are off a little bit. When there's no gap, the corners will look like this:
Attachment 55537 Attachment 55538
And here's what happens when there's a gap in cutting the miter...in this case the gap was about the width of the saw kerf (3/32").
Attachment 55539 Attachment 55540
There ya go...