Gone are the days when buying a desktop replacement meant making massive compromises on performance as compared to a standard PC. The same components found in the average desktop can now be found in a desktop replacement model. Pumped up performance equals great power consumption however, with most desktop replacement systems having very limited battery life for when you do want them to be mobile. To counter this it is often possible to get and additional battery for a couple of extra hours of work.   If your desktop replacement is going to be in regular use, then you want a lot of space on the hard disk. Go for a model with 80GB if you can: you'll get through the space quicker than you think. Another possibility is an external drive, which you can carry with you all leave back at base, depending on the nature of your trip. Most desktop replacements use 15 inch or larger LCD panels, which also turn to have a higher native resolution than a standard notebook: SXGA+(1400*1050) or even UXGA (1600*1024) resolutions are now to be found in desktop replacements which, along with higher specifications graphics chips, has opened them up to a number of new users, such as designers. Go for as high as spec as you can get for your money, and check the quality of the speakers as well