I'm not looking for an idea for a map, I already have that, and it's called Size Matters. What I'm looking for is an idea for the rest of it. I can't just discontinue this, it got a reasonable amount of subs, and that was just a demo. Just so you don't have to go and play it, and to prove this isn't just to get you to play it, here's the general idea: You are a tiny person in a normal sized office, and you have to make your way around certain obstacles. You start off on a desk, but I really don't know where to go from there. Any ideas?

Through the door on the left.

Sorry. I had to.
Anyways, maybe you could leave the office and walk out to a giant view of an underground test shaft and enter a test sphere to preform maintenance or something, then get stuck after something goes wrong.

Google search any of the "MicroMachines" racing games/similar stuff... If I remember correctly they were all based around the concept of racing your tiny little car around mundane surfaces. I think I can remember a desk/office race that took you through and around an office style environment that was alot larger then yourself. It might give you the inspiration you're after ??

How about a section inside the "workings" of a standard funnel (ie; attempt to re-create the model in over-sized brushes) using the funnels "eddie-currents" as mini-funnels to solve a problem and escape...

There was a Toy Story game on my old GameBoy that had a section where you had to navigate the inner workings of a Vending Machine and Claw Game, had hazards of moving pistons (crushers), falling drink cans, coins tube warp pipes (vactubes) and electric sparks (fizzler/death fields)...

Is that the type of ideas/ things you had in mind ??

While your idea is by no means original, I would say the best thing to do is to explore the relationship between Aperture and its test subjects. So that would mean areas of the "behind-the-scenes" part of the facility that would enormous in size. You could even give a new perspective to the Rattman dens that are found in the walls.

Basically, you have given yourself a challenge which is far above where I think you are. I suggest you make some standard test chambers to flesh out your creative style. Then you can start on the strange things. You can't really do strange until you know what normal is.