I considered putting an engine-killer in so that it would kill the ignition if the kickstand was down while in gear...but doing so would have just too many points of failure, potentially leaving me stranded somewhere should a relay, kickstand switch, or neutral switch fail. Putting in an audible alert wouldn't really work either, a lot of the time I have the radio on, and I run the chance of just not hearing it.
So I was left with a visual alert. I decided to put a very bright flashing red light in my field of view, that would flash as long as the bike ignition was on, and the kickstand was down.
For the switch, I decided I wanted to use a sealed unit, to avoid any mechanical parts that could cause failure. I used this sealed, normally closed reed switch. I also got this magnet which is matched to the switch. This switch is normally closed, but opens when in the presence of a magnet. Placing the magnet and switch in such close proximity to steel (the kickstand and mount) weakens the effect of the magnet considerably, so I had to have the two quite close, with tight tolerances.
I ground the flanges off the switch and the magnet, cleaned and sanded the spot on the kickstand I was using, sanded the switches, and epoxied them in place. Once that epoxy had set, I added some more epoxy around the perimeter of each unit, for extra adhesion and protection from foreign object damage:

I may paint the epoxy black just so that it doesn't stand out so much against the black metal.
As for the warning light, I used this blinking LED from SuperBrightLEDs. I've used them for quite a few LED projects in the past, and they are quite good quality. They also sell panel mount bezels for mounting the LEDs in panels, which I used. The LED requires 5 volts, so I used a 7805 voltage regulator to bring the bike's 12-14 volts down to the 5 volts the LED requires. Because the LED has flashing circuitry built into it, it does not require a resistor.
I installed the LED in the housing of the right speaker, and the voltage regulator inside the speaker housing, where it is protected from accidental bashing while working in the fairing. It works quite well, and it's EXTREMELY bright - there is no way I can miss it when sitting on the bike. It doesn't show up in the picture as bright as it looks shining into your eyes. Incidentally, just in case you're wondering, that's the antenna for my satellite radio that's mounted on the speaker above it.
