I wanted to address the portability of the ION platform, so I figured what better way than to design a full computer into a backpack. Due to the $500 budget, I needed to scrimp on the components, but I think I designed a pretty decent shell. The image for this idea is here:
The way I see it, you could easily house a decent laptop battery to power the structure (or use the AC adapter provided with the motherboard) in the base. I estimate this would be about $110.
A 17" Monitor would be about $100, and would fold over the left shoulder to provide it at a decent distance. The keyboard and mouse would swing around from the lower-right of the backpack, and should cost about $27
Since this is portable, a SSD drive is a must, and I found a decent 32GB one (not huge, but it's portable) for about $110. The RAM could be fairly basic, and I figure about $44 for this.
This gives about $100 to design the backpack and swing-arms. The arms should be able to fold into the backpack to create a clean package when not extended.