If you're big enough of an Apple fan to own an iPod, you probably already have a good idea of what the iMac G5 is all about: the familiar white sheen, the brushed metal L-shaped stand, the brilliant widescreen LCD. Throw in Apple's wireless Bluetooth keyboard and mouse and you've got a scene of Kubrickian merits. Only the cable that runs from computer to an iPod (or printer or digital camera or PDA) disrupts the sci-fi harmony. In terms of actual computing power, it occupies a nice space between the PowerBooks and the dual-processor G5 PowerMac.

The coolest enhancement you may not have heard about is the automatic Mac-to-Mac upgrade software. When you start the iMac for the first time, it asks "Do you already have a Mac?" If you say yes, it asks what kind and then, if it qualifies (running OSX, has native FireWire support, etc.), it asks you to connect a FireWire cable. It then sucks all of the pertinent account information, favorites, applications and documents from the old computer to the new one, virtually cloning it head to toe. I tried the migration with a PowerBook that had about 5GB of personalized data, and it only took 15 minutes or so before the iMac was up and running everything the PowerBook was meant to. Only one application needed to be re-registered, and the software even told me which one that was. I don't know much about the legal side of software licensing, but moving even expensive apps (we won't name names) was frighteningly easy. By the way, none of the data on the older Mac is harmed in the process.

One of the big PC trends right now is the "desktop replacement," that is, a notebook with a big screen and a processor meant to be plugged in: they don't get very far on batteries, but as a fully enclosed system with integrated wireless networking, they're far more convenient around the house. The trouble is, every notebook is more expensive than its similarly powered desktop-PC equivalent. The new iMac is the "desktop replacement" replacement: most of the positive notebook attributes (except, of course, that you wouldn't take it to Starbucks) with a much smaller price tag.

When I say smaller price tag, I don't mean it's cheap. In fact, if you opt for the Bluetooth kit (short-range wireless networking) and its compatible wireless keyboard and mouse, you will pay an extra $100 (Bluetooth kit alone is $50). To make sure your purchase makes sense in a year, you'd probably opt for the middle or higher of the three models, because of the processing power and also because of the SuperDrive, which can burn DVDs as well as CDs.

Even after a lot of customization, the 17-in. iMac G5 is still perhaps $1,000 less expensive than the 17-in. G4 PowerBook it outperforms. So, if the reason you're shopping for a notebook is so you can use it at the kitchen table (or even at your house but also your summer rental), save some money and put the rest into the iMac G5.