I have a MacBook Air. I love this device, but it's a couple years old and anything that gets a few years old is liable to have issues.
I also have a Kindle I bought more years back. After I had it for a couple years, it had issues, too. The power and data cable was made of this really odd kind of plastic. It felt silky instead of shiny/slippery like plastic, and also it wasn't rubbery. I loved it until it started to crack. There's something about that plastic that gets to be a couple years old and then it deteriorates. Eventually, I got a new cable from the guys at Amazon. Good thing b/c the cable insulation was badly degraded by that point.
Fast forward to about a fortnight ago. I'm checking out MAKE magazine and see something about this stuff called Sugru-a sort of Play-Doh for grownups. So, I bought a sample pack thinking I might find some use for it.
Last night I did. My MacBook Air cable insulation started cracking in the same place and after the same fashion as my Kindle cable.
I remembered the Sugru that I bought. I read the instructions, got the stuff out and started using it. I spread the stuff out in my fingers into an elongated blob, then squeezed the blob around the cable. With the end of the cable that had started to crack fully wrapped in Sugru, I rolled the cable/Sugru between my hands to make it thinner and more even. I suppose I could have been a bit more exact, but it was a first experiment.
This morning the stuff cured and now it has this silky/rubbery appearance and the cable has a more robust strain relief that looks as you see on the right. The stuff is flexible and it sticks quite well to the cable. I'm rather pleased with how it turned out.
A fresh pack of this stuff belongs in any bodger's toolkit alongside the duck tape.