So i was looking at some flying robot designs, just out of curiosity. I ruled out helicopters and planes: they require too much precision in crafting and are too complex.. But alternatively an airship could probably be built :)
I've read on wikipedia that a square meter of helium can lift about 1 kg. A square meter means a big balloon, but a Kg is plenty of weight for electonics!
If you use light components, you can probably stay under 0,5 Kg or even less.