I needed something to drive "brads" into tight spaces so I came up with this.
I ground the point off an impact center punch (for wood) and magnetized it.  

The thin panels are a little thinner than the slot so I could assemble them faster with wet glue.   When I glue the panels into the frames, I'll use small nails to hold the panel pieces against the outside of the slot (the pressure is also like clamping a glued joint).   In order to drive these 3/4" finish nails in a tight space (too tight for a hammer at the edge of panels) I decided I needed an impact tool.   So I ground the point off an impact center punch for wood and magnetized the driver tip. I can also use this on drawer bottoms.

3/4" nail magnetically held to front of impact nail driver tool.

Here the glue is wet, frames are clamped, and I'm using the impact nail driver to drive in nails from the back to hold the panel tight to the front (outside) of the frame.   You have to hold the nail in place on the frist snap with a pair of sharp nose pliers.   Then a couple of snaps with the impact and its down.

I'm driving the 3/4" nail in at about 45° so it won't come out the front.

Closer look, you can see the gap at the back of the panel (this side).

Nail down.   And you can see the gap, the nails are doing their job.