Why not, when you run out of stuff, you press a little button, and our little beeping pal the office bot comes round, and it will give you what you need. Plus it has an anti-plundering device, so that if, say, you decide you need 25 pencils in one day, it will only give about 8 or 9 pencils, unless
your boss says otherwise, or if you override its controls.
It would be like a little train, it runs on a rail, and when nobody needs it, the wee thing will just go into a little cabinet, where it can be re-stocked if everyone asks for 35 pencils each in one day.
And it will have an identication system, so that the cleaners don't come in and plunder office supplies, or stick them up handy orifices, by fingerprints, or something like that.
Yes, I know this isn't the most original idea around, but I'm just imagining something like R2D2, coming round, giving you pencils, pens, paperclips, then doing the cool whistley thing, then going back to its cabinet...