Here are some bass related toys that I happen to like.

Hipshot Bass Extender

This is one of my favorite toys. The Hipshot is a special tuning peg with a lever system that lets you tune a string down a few notes at the flip of a switch. Normally, you set this up on a four string bass so that you can quickly tune the E string down to an open D. This is a very cool and common application of the Hipshot, and I have one on all my four string basses.

You can kind of see the lever sticking out from behind the headstock of my Fender Jazz basses in that picture up in the left corner. To use it, you just reach up with your left hand, and flick the lever with your thumb in a very fluid motion. The low note is tunable, so you're not stuck with a whole note de-tuning, but the open D tends to be most useful for the songs I play. It's almost as easy to flick back up to E, and the Hipshot stays in tune very well in both the D and E configuration.