The Filabot was something on Kickstarter last year, it featured a grinder and an extruder so you could recycle mis-prints and use bottles and other plastics.

Sadly, they still have yet to get the grinder working correctly, and as far as I know, there is no other similar unit either in production or for sale.
The main feature that I would be looking for would be the grinder. I would rather just grind up printed supports and things that didn't come out well as opposed to buy plastic pellets and have all my supports and botched prints go to waste.
This is a major problem with ABS plastic compared to PLA because PLA is plant-based and will biodegrade over time. ABS is artificial and will not, so throwing away prints made with ABS is eventually going to cause a problem for the environment.