With our color printers, I seem to have dozens of empty BCI-6 cartridges and CLI-8 cartridges and feel sad about throwing it away. The top two recyclers, "freerecycling.com":http://freerecycling.com don't however recycle these, but they do higher runner bubblejet cartridges and also HP cartridges.
So, it seem like they need to be thrown away. Sad. It is not so much the $0.10 you make (for a $9 cartridge!), but that it is another thing that goes into the waste bin as you can see from their "price list":http://www.freerecycling.com/Ink_Recycling/Cartridge_Price_List.htm.
"Staples":http://staplesrecyclefored.com does have a non profit thing they do which includes a $3 per cartridge donation. Again, their "list":http://www.staplesrecyclefored.com/eligible.asp doesn't include those that I use. Too low volume.