Dittis on that. Made a few Christmas ornaments, and then realized I had neither the patience, or the interest, in making little frilly things that required a TON of intricate cuts.
Like so may others, I hardly ever use my biscuit joiner, but found a really good use for one. I built a large version of Festool's MFT workbench that has a CNC machined MDF top. I needed to fasten the top to the frame, but did not want any screws anchoring it from the top, down into the frame. I bought some "Z-clips" that ride in a groove on the workbench frame and screw into the underside of the top. The biscuit joiner was perfect for making those slots. (Thankfully it is a Harbor Freight model, so I paid next to nothing for it ...)
For all of you lamenting the fact that you dropped two bills or so on a Porter Cable biscuit joiner, check out the Lamello models at just shy of $600 ...
http://www.homedepot.com/p/Lamello-7..._sku=203945246