I'm actually building a wooden frame to my boards (4x4). Just some hinges, an opening so I can fold the frame (it's easier to transport that way...) and an simple aluminium cross which you can get from IKEA for a euro. Total cost, including some coloring and nice brass hinges: 12 euros. Working time: Will be announced, but since I've pre-cutted the wood already, I'll reckon it takes about one hour.
This is the wood I got (I've forgotten the word in english, so if anyone want's to help out they're more than welcome):

Its 69mm high, so it saves you some back-breaking dice chase on the floor

I am to get all the pieces together, I'll probably have the time for that this weekend. Only issue is whether to put the hinges on the outside, or the inside. Outside hinges may hinder the folding, while inside hinges will leave small gaps in the frame.