The new iMac blurs the lines between portable and desktop computers. The iMac is similar to a portable computer in having the computer built into the display. To use it, you have to plug it into a power supply and attach a keyboard and mouse, steps not required for a portable. The new iMac introduced yesterday is said to be 8 pounds lighter than the previous model, though, light enough that you could carry it around almost like a portable computer. The extra minute of setup would be an obstacle for someone who was actually traveling, but not such a big deal for someone moving from one desk to another within the same building. The lighter, simpler desktop computer lends a little more impetus to the trend away from permanently assigned desks in offices. Workers can still use desktop computers even if they are not working at the same desk all day long.