The LA and I enjoy the occasional (read: regular) game of Arkham Horror, which, while fun, is also space-hungry. Our largest table is approximately 3 feet square (EDIT: just measured; 3'6"), and this is (barely) large enough for our four-investigator games. However, for Christmas, the LA's father was kind enough to buy for us the Dunwich Horror expansion. This adds a number of cards, making some of the locations rather more interesting (and in some cases, posing the risk of "killing off" at least one location permanently), a few wrinkles in the mechanics (apparently, spraining one's ankle twice was fatal in the 1920s; who knew?) and an extra board. While much of the expansion can be "dropped in" without the new board, it's reportedly best with the board. This presents a problem.
I have, however, already worked out how to fix it. What I shall need for this is: a four-foot length of piano hinge, two four foot by two foot six sheets of MDF (sufficiently thick for me to install the hinge such that it's flush on the pin side), about a square yard of felt (preferably something I can easily glue down, although staples would also work), four 18" battens, and the usual screws and suchlike. With these, I can make an expansion tabletop. With some extra felt and sufficient edging, I can make a most excellent gaming surface.