They're everywhere, even in your own backyard.

Got a new client this afternoon: fellow motorcycle enthusiast preparing for a track-day tomorrow.
Proud owner of a shiny red 07 Ninja 650, I met "Quentin" over on the VADriven.com message board. As it turns out he lives about 5 miles from me.
I agreed to help him swap out is chains and sprockets on the one condition that he learns as much as he can from his track experience tomorrow. I didn't snap any pictures this visit because we were pressed for time, but hopefully he'll come back for a follow-up.

The whole process took a little over 2.5 hours. It was about an hour more than I expected it to be however half the time was spent trying to secure the bike and get it in the air. Lacking bike lifts myself, it didn't help matters that his 650was without a centerstand. However after a good bit of poking, prodding, and searching, I determined that it would be safe to lift the bike with a car jack and 4x6" board under the swingarm at the pivot point. I had him hold the bike while I got the back tire ever so slightly off the ground. Satisfied with the balance, I secured the bike further with ratchet straps around the front forks hung from the garage door rafters, and car jackstands under the footpegs. The weight of the bike balanced well across all 5 lift points we proceeded to remove the sprockets, chain and wheel.

The front sprocket came out first, and without a hitch. There was a good build up of tar and grease but not much else, which is a good sign of a careful owner. The toughest part of the operation was getting the sprocket retainer nut off. Thank god for air tools. The chain slid right out with the sprocket, then the rear axle was unbolted and the wheel slid right out. A cutting wheel made short work of the chain and while I cleaned everything up and put the new front sprocket on, Quentin removed and replaced the rear sprocket with an anodized red aluminum replacement. I positioned the chain on the front sprocket, slid the rear wheel on, mounted up the chain properly and realized, "holy crap I can't find my homemade chain rivet tool." I had made a riveter out of part of a pipe flaring tool and some c-clamps, but it was nowhere to be found. So I reverted to my Motion Pro chain breaker/riveter tool and it seemed to work well enough. It didn't mushroom or curl the rivets like my homemade tool does but there was obvious squishing of them, so I'm sure they'll hold.

Chain tightened, wheel aligned, and bike lowered, he took off ready for his track-day ride. Hopefully the weather holds out and he gets a whole day of riding in. Good luck buddy, and ride safe.