I'm a bit crafty so I've actually made a few things.
I kept putting my 510 down, then I'd go to another room to do something else and realize I didn't bring it with me, that gets annoying and tiring very fast when you're on crutches LOL.
I used some very fine cotton yarn and crocheted a tiny little tube and lanyard that fits my 510 perfectly and wear that pretty much everywhere. I even remembered to create an open spot for the button.
And now that I got my sb I decided to make something for it too, had some very thin denim material and some velvet, so I've sewn up a nice soft pouch for that. Fits like a glove, just need to figure out the lanyard for it.
Also had some leftover sculpey sitting around so I made a couple holders, lined them with some velvet, and they hold several 510's or the sb.