Sugru is a strong, sticky, flexible, adaptable substance that's perfect for improving and patching your favourite stuff, including laptop power cords that tend to lose their sheathing with standard use. An Instructables user shows how to re-wrap your cord at the brick.
The "fix" is pretty simple, really, and only requires a bit of precision in applying the Sugru to your cord break in just the right way, then the patience to let it sit, unbent, for about 24 hours. Once that's done, the Sugru now bends and protects as if it was always part of your power supply.
Sugru goes for $US9 a packet of six packets of 5g each.
Repair an Exposed Wire with Sugru [Instructables]