Well it's kind of hard to catch the flashing lights with pics, but if you insist I can try. Basically each of the individual brake light bulbs flash in an alternating sequence about once a second or maybe half a second. Just like your blinkers.
I bought my flasher at the local Napa Auto Parts. I couldn't find the part on the webpage but I will post the link anyway. It has a store locator and stuff, and you could probably email them to order a #537 Flasher.
http://napaonline.com/cgi-bin/ncommerce3/ExecMacro/NAPAonline/homepage.d2w/report
The flasher is an electronic 3 prong. also available elsewhere for $20-$30. It is black plastic 1" square and 1 1/2" tall with 3 male blade wire terminals coming out. You just find your 2 Positive wires that go to each brake light, cut them. On my GSXR it is a white wire with a black tracer. Put a standard insulated female wire terminal on each bulb wire end and connect to the two terminals labeled L on the flasher. Then put a wire terminal on one of the other signal leads you cut coming from the bike to the light. Put that on the X terminal on the flasher. Wrap the 4th wire end in electrical tape and put a small wire tie on it to prevent shorts. Also wrap some electrical tape around the terminals on the flasher so it can't short out either unless you used the insulated wire terminals. Then you should be okay. I also wire tied the whole flasher to the brake light wiring so that it can't bounce around. That's it, took me like 5 min.