I made this just now with the kids, it's the circuit from a cheap USB hub in a Lego enclosure. It looks cooler than the original, and has optional minifigure cable holders!
Step 1: Bye, Robot
I got given this robot USB hub last Christmas, but never used it as its superbright LED eyes were a bit distracting! It didn't move around or anything, so I decided to have it apart and put the hub circuit in a nicer case.
It dismantled easily and as you can see stripped down to just the hub board and connected LEDs.
Step 2: In Case
Earlier today I wondered how closely the circuit board dimensions would fit with Lego - to my amazement it was a perfect fit, being almost exactly 6x6 Legos square (if that's how you describe it).
The kids helped me dig out all the black bricks and we experimented with different layouts until we got the smallest size possible.
The glare of the LEDs is diffused nicely by the clear brick now, and it blends in well with the other junk on my desk.
I have lots of those short USB cables lying around and minifigures (as I learned from a recent instructable) make the perfect holders to keep them at the ready.
A quick & fun saturday afternoon make that I'll now use daily at work, and can redesign at any time!
Step 3: 20 Minutes Later
As soon as I hit the Publish button I remembered a recent article about recreating old tech in lego, and decided to give this build the retro tv/radio treatment!
The diffused blue LEDs give it a nice TV screen glow. I imagine it will stay in this shape for at least an hour.