Have you seen the raised beds by Gronomics? They are very nice as well and I think less expensive. But these would be a very easy DIY project for about 1/4 of the cost!

Here is a link that might be useful: Raised beds

It looks like the boards are held into the corners by slots?? you might be able to do that with a router or a biscuit cutter(the tool kind, not the dough kind) :)

I could not find anything explaining how the boards were attached to the corner posts. It did not look like brackets were used.

Thanks MNMom - yes, the Gronomics raised beds are much cheaper, and are supposed to be available at Home Depot, so I will take a look next time I am there to see how they are connected. Lunarmoth, I thought the same as you - what is holding them together so the weight of the soil doesn't push them apart? The really expensive ones (Carolina Garden System) have a patented track system which is probably not very easy to duplicate. However, I found a third system online that I think would be easy to do. The ends are notched halfway through the wood and then a hole is drilled through each piece. The ends overlap and a long, metal rod is inserted through the lined up holes to hold them in place. That would be super easy to do, I think. I have some time yet before I need to replace my pine ones, but its fun to dream :)

Here is a link that might be useful: Earth Easy Raised Beds

lunarmoth, there was a pdf for assembly where you order the kit. It looks as if a saw was used to cut a slot down from the top for the side boards to slide into, then caps applied.
Tammy

actually that was for the elevated bed, the raised bed slots ar cut from bottom up, but not thru the top, assembled then turned right sides up, so the ground holds the boards up in their slots. I like the looks of these as well.
Tammy