As I've made my way through MacBooks, MacBook Pros, and MacBook Airs over the years, I've gone through a lot of power adapters. They typically wear out and fray in one of two places: Either near the MagSafe adapter, up near the MacBook, or down near the transformer. Recently I became aware of a new product, the Python cord protector, that purports to resolve that latter issue.
There's no question that over time, power adapter cables can wear and fray. Replacing them isn't cheap — $80 for a new Apple-branded adapter. For $11, you can have a bit more peace of mind with the Python cord protector.
Apple's MagSafe power adapters may save you from breaking the cable where it connects to the MacBook, but it doesn't solve another issue: When you wrap the power cable around those two tabs that pop out of the transformer, or when you're just moving it around, the cable at the base of the transformer can fray as well. Apple reinforces it a bit, but probably not as much as they should. As such, that cable can bend and the casing around it can snap open. That's an electrical hazard.
I've seen (and tried) some MacGyver-level solutions, like wrapping duct tape or electrical tape around the base to keep it from flexing: Cheap, ugly, and not always effective — electrical tape flexes and bends too, after all.
The developers of the Python cord protector have another solution. They've developed a silicone rubber band that wraps around the transformer and firmly reinforces the cable. A long, slender silicone sleeve extends from the band to wrap the base of the cord and the couple of inches above it. It's open, wider at the bottom, and tapers in a spiral all the way up to the top.
You feed the MagSafe end of the adapter through by flexing the Python, then wrap the Python snugly around base of the cable before stretching the band in place over the transformer. It only takes a minute to put on, and it works as advertised.
The Python is an elegant solution that looks a lot better than duct tape, and works better too. And for $11, it's certainly cheaper than a replacement AC adapter.
It's not just available for the Mac — the makers of the Python cord protector say it'll work with PC laptop adapters as well. It's available in black or white.