[Beta]

I was toying with having a character (that has a lot of free knowledge skill points) taking Technical School Education, and picking up a bunch of professions which could either be somewhat useful, or useful as parts of infiltration/disguises/cons.  An obvious one would be 'Janitorial Science' (because who looks hard at a cleaner who seems to know what they are doing).  A bit of 'cook' just to avoid Stuffer Shack for meals. 

Do you have professional knowledge skills that you have found fun, useful, or interesting?

[ZeldaBravo]

Architecture (Building Layouts);
Power lines;
Electrical circuitry;
Hardwired networks;
Industrial safety;
Industrial routine procedures.
Found those useful at least once each.

[gradivus]

Atzlantechnology

because you never know when you might need to know which door not to open in the pyramid

[SmilinIrish]

Forensics - Find your own evidence, the knowledge to clean your own away

Police Procedures - Know what to expect from police, talk the talk if you are ever impersonating one.

[Stoneglobe]

Journalism and or photography/fiming - have lost count of the number of times we've managed to get access to areas or interview witnesses using that cover. It's great for not raising suspicion in areas that aren't high security. Mix in some forgery to provide press credentials and you're really going somewhere.

[Hobbes]

Drafting (Read Blueprints of all kinds)
General Contractor (Zoning, City Records, What firms do what specialty work...)
Consultant (Generic business babble and buzzwords as well as knowing who and how stuff gets done)