Traveling with your notebook outside the United States presents a whole other set of issues. You have to deal with customs issues, power issues, connection issues—you name it.
The first thing you have to deal with is customs; you don't want a customs officer telling you that your old notebook is a new purchase and that you have to pay customs on it. For that reason, it's a good idea to carry proof of purchase with you, in the form of a copy of the original store receipt. If you're using a company-issued notebook, ask for a letter signed by a company officer certifying you to carry company property internationally. Without such proof of ownership, you may be forced to pay a duty on your notebook.
Then there's the issue of restricted information. Believe it or not, the United States has laws against exporting certain technologies and technical data—and the fines are quite severe. This typically isn't a problem, unless your notebook contains files dealing with technical designs, manufacturing processes, and product specifications. (Certain encryption programs may also be in violation of security regulations in some countries.) Unless you absolutely need these files for business while you're abroad, it's best to delete them before you leave, just in case.
Finally, there's the power issue. Electricity is electricity, but power standards and outlets differ around the globe. You may need a power adapter (step-down transformer) to convert other countries' 240V power to the U.S. 110V standard. In addition, different countries use different power plugs and outlets; there are nine different plugs in use in various parts of the world. Make sure you have the correct adapters for the countries in which you'll be traveling.