This is an almost entirely made from scratch solution that didn't cost me anything to make. Of course it helps if you already have some tools. :)
Step 1: Parts list
a cheap handlebar mounted reflector or similar thing. Mine came with my bike as a freebie to mark the place where your headlight should go.
two machine screws with matching hex nuts or the like.
a means for cutting metal, I used a jeweler's hand saw
pliers or metal bending tool
Step 2: Measuring the metal
I've pressed the back of my gps into the tool to capture the form I need to make out of metal.
Step 3: Cutting the metal
Guesstimate the amount of metal required and scribe out some cutting lines with the point of a safety pin.
Using a c-clamp, clamp the metal to a work surface and then use the jeweler's hand saw to cut along the scribed lines.
The jeweler's handsaw is an amazing tool. You can cut almost anything you want with it. It requires no physical strength, only zen-like patience. Admittedly, it takes a few tries to get the hang of using it. You can purchase saw blades for a very reasonable price at Widget supply (www.widgetsupply.com). Periodically coating the blade with beeswax helps prevent breakage.
If the metal is too hard to cut, you can soften it by placing it on a stove top, cranking the heat and letting the metal sit on top of the flame until it turns burning bright red throughout. Then, with some tongs, drop the metal into cool water. It will sizzle and look oxidized, like this metal does here, but then afterwards the metal will be much softer and more pliable and easier to cut.
If you're using metal with unknown constituents, be careful not to breathe any fumes that might be generated by super heating it. So, turn on the fan, maybe step outside for a bit.
Step 4: File the edges
Step 5: Form the metal
Just bend the metal so that it creates an open box like shape around the gps.
Then crimp the tips in a bit so that the gps sits snugly inside the shape, yet is easy enough to slide in and out with a little push.
Step 6: Drill screw holes
Use the handlebar mount as a screw hole template and scribe the positions of the screw holes into the metal with the safety pin.
A drill press is ideal. At the very least, clamp the metal firmly before drilling. The scary thing about drilling metal is that sometimes the drill bit can catch in the metal and cause the metal piece to spin around wildly. So you definitely want to clamp it down before drilling.
The awesome clamp shown below is available at Widget Supply (www.widgetsupply.com) for around $15. You can position your work fimly at almost any angle with it. It's one of my favorite tools.
Step 7: Assemble it
You can easily saw off the excess screw length with the jeweler's hand saw for a neater appearance.
Step 8: Paint job
Put the whole thing inside of a paper bag and blast it with spray paint. The paper bag is good for containing the overspray. This especially good when you live in a small apartment.
Step 9: Finished
My only qualm is I wish I had chosen a handlebar mount that had one of those quick release things so I could remove the entire mount without using a screwdriver.
After all is said and done, I will still probably try to get a new one from Garmin, if they ever get them back in stock.
But hey, it didn't cost me anything and it's not too bad really.