Surge protectors are also called surge suppressors. But they really don't suppress the surge. They contain small disk like device called a Metal Oxide Varistor (MOV). It is a form of semiconductor. The device has a threshold voltage that, when a transient spike voltage reaches that point, causes the device to conduct. It is wired from the hot side of a circuit to ground, so a voltage spike is sent to ground instead of into your electronic device.

4.0 out of 5 stars Best of the cheap surge protectors, April 4, 2005 Review of: Tripp Lite TRAVELER Protect It! Surge Protector/Suppressor 2 outlets (2 Transformers) For Laptop Use, Direct Plug-In 1050 Joules (Electronics) at Amazon.
By David A. Grim

Basically it's the best mov surge protector for a laptop. mov's are little disks in the surge protector that litterally pop when a surge spike happens. If you can handle the small weight difference the white isoblok 2-0 is better. It is a lower joule rating but offers a 0 sec. clamp time and lower voltage threshold. A spike only lasts around 1ns and a surge 3 ns. This adapter is ok at under 1ns. It is at 150 volts though and the isoblock is at 140 volts. Remember that not all power out of a socket is at 120 volts (110 in Japan). Either way you would need a new adapter every year just to be safe as the mov's are only worth 1 spike. Its far cheaper than buying a new laptop.