I've found this useful for lining up ignition switch lock when you and your eyes are too old. A plumber's tool from Ridgid.

 

Not unique or exotic in any way, but probably the most often used tool I have.
Leatherman Wave.
I almost feel naked without it on my belt.

 

jhnmso, what is that doohickie? Is it a boroscope?

 

I thought of this picture you posted the other day when I saw this thread tonight. I was looking at Sears just today for this tool with no luck.
Now THIS is ghetto, you mention having to fish the 3mm allen out from behind the engine, well, when I first started messing with my AFR I thought I would drop that 3mm behind the engine in no time, which I promptly did. So, I got a thin string, taped one end to the allen wrench and tied a loop at the other end that simply slips over my finger. It's cheese I know but I haven't dropped it since!

 

I have used this to fish wires in finished walls when building our theatre. It's BRILLIANT!

 

http://www.ridgid.com/Tools/SeeSnake-micro

 

A few of mine:

 

I like the dust cap puller. Dumb question though: what application does the relay w kill switch have?

 

I'm gonna guess to toggle the jumpers that park the ICV for setting the idle?

 

tie rod puller, spark plug pliers, ride height wrench.

 

sound meter and HID flashlight

 

Socket for mounting 4 piston 993 calipers onto the rear of a 1984 Carrera:

 

Front dust cap remover:

 

Blunt-end wrench:

 

Damn you Ed, your last picture just made me have a craving for a Mojito.