Most useful tool that you didn't realize you needed

[Outlawmws]

What is he into?

If he's into fixing up "old stuff" and has to deal with rust, an electrolysis setup: (Bucket, a half dozen 2 ft chunks of re bar, an old school battery charger, some PH+ spa chem or washing soda, and a spool of soft steel wire.

That and a soft/fine wire wheel, preferably bronze.

 

[BJ42LX]

I got this as part of a two-fer deal on a nice die grinder. I've ended up using the sander more than the die grinder. Very handly tool when you just need to clean something up.

 

['52Chevy]

offset double box wrenches saved me alot of hassle the other day.

+1! I love these things so handy to have! I may have a set of USA made ones brand new yet.

 

[nexum1919]

a good headlight
not the asian $20-$25 stuff, i graduated from those real quick

i have two zebra headlamps:
H502d good spot with some spill around. used for general work
http://www.zebralight.com/H502d-High-CRI-Daylight-tint-AA-Flood-Headlamp_p_96.html

H51c uniform flood, useful for close-up work or in complete darkness to see around without tilting or bobbing your head.
http://www.zebralight.com/H51c-Headlamp-AA-85-CRI_p_60.html

what a difference to have light whereever you point your head, no shadows. i even pull them down right next to my right eye for deep engine bay work. no more drop lights, shop lights for me.
i feel like i can breathe easier while working with those things on my head. working with insufficient lighting is like holding your breath...
obviously get the sanyo eneloop rechargeable AAs.

they have great color rendering, stuff actually looks the same color as in daylight. they seem to magically reveal the tiniest cracks, scratches, subtle undulations etc.
do yourself a favor get rid of those horrific white leds...