Where you travel regularly overseas there may be problems with power supplies. Happily, today, most computers and portable printers will operate on 115 volts or 220/240 volts and so voltage is not an issue. But power sockets are. I check on http://en.wikipedia.org/wiki/Mains_electricity_by_country before I go to see what adapter I need.
Another trick where you work in UK/Europe and the USA is to replace the whole power lead.