Precision Biscuit Joining

I have a Porter Cable biscuit joiner that I get to use on occasion.  I pretty much use biscuits for three purposes:

1. To align two pieces of wood for gluing; emphasis on the aligning part.  If I were to glue together several planks of wood to make a tabletop, I'd definitely use my biscuit joiner to align all the planks for a stress-free glue up.  The biscuits keep pieces of wood from slipping (wet with glue), and if you cut them precisely, you have fine-furniture quality alignment in those glue ups.
2. To create a jig in my woodshop.  It's quick, gets the job done, and I'd rather be building furniture than spending a lot of time with elaborate joinery.
3. Prototype building.  If you're needing to build a prototype of a piece of furniture, it helps in achieving a  quick and dirty version of the piece you plan on building.

For our purposes here, I want to talk about a simple jig I use to achieve (1) in my above list; precision alignment.  Honestly, I'm having a hard time actually calling it a jig, since all the jig really is are two screws and a piece of plywood.  Note the two screws and plywood.

Yup, this simple bad-boy achieves one thing and one thing only.  It keeps the biscuit joiner stationary during your cut, and the only thing you need to hold still is your work-piece.  All the error introduced in cutting biscuits is by moving the biscuit joiner during your plunge cut (when it's not screwed down to a piece of plywood).  Even with the steadiest of hands, there are little errors you're introducing into your cuts by moving the biscuit plunger AND holding steady your work-piece.  Why make it harder on yourself?  Just anchor this bad-boy down with a couple of screws to some plywood, and VIOLA, you have near perfection in aligning your slotted cuts!

Here's a sample sequence of cutting biscuit slots.  The piece is the top to one of  my message centers.  It's pretty self-explanatory.

Cutting the frame...

Cutting the biscuit slot on the top...

Here's the biscuit alignment of the top to the frame.

BAM!  And the alignment of the top to the frame were perfectly aligned.  Imagine if you did this to glue up your table tops?  There is a lot LESS sanding involved when you cut your biscuit slots this way.