After sorting out your Lego's you're left with a huge pile of axles… I made a solution for that problem
Here's the Lego NXT Axle Sorter
Put you're axles into the loading container and the robot does the work for you
Here are some photos if you're interested in the design. It's not much but with a little help of the video you can make something similar I guess.. Otherwise, please leave a comment
This thing I used to dispense only one axle at the time into the machine;
NXT Programs: Lego NXT Axle Sorter
If you have any questions, please let me know!