Sex and power.

It's an irresistible combination, and Apple CEO Steve Jobs knows it. When Jobs introduced the PowerBook G4 at January's MacWorld Expo in San Francisco, he said Apple's goal was to combine the sex appeal of the Sony Vaio (a Windows-based notebook computer) with the power of a Mac desktop computer.

Although Jobs tends to exaggerate at these semi-annual extravaganzas, the newest PowerBook is the real thing. Here we have a laptop Mac powered by a 400 or 500 MHz G4 chip, featuring a 15.2-inch-wide screen, a DVD-ROM drive, 128 megabytes of memory and an advertised battery life of five hours - all encased in an inch-thick, 5.3-pound titanium shell.

And if the sex and power aren't enough, add money to the picture, as in how little of it you'll need to buy one of these dreamboats. The 400MHz model starts at just $2,599 - practically a steal for a professional-class notebook with these credentials and about what you'd pay for a mid-range desktop Mac without a monitor. It's even cost-competitive with high-end Windows-based notebooks.

While I have always preferred desktop Macs to mobile ones, my encounter with the on-display PowerBook G4 at the Mac Home and Office store in Towson had me wishing I was a businessman who needed to travel by air frequently. There can be no better way of passing the time of a long flight than watching a DVD movie on this thing.

My main concern about this machine was that it would be too hot - as in high temperature. Its CPU, the "brain" of the computer, is a faster, more advanced chip than the previous, G3-powered Mac notebooks, but it also consumes more power and runs hotter.

The bottom of the PowerBook G4 was quite toasty, but only in the area of the CPU. And the folks at the store said they have had the machine plugged in and running non-stop, nine hours a day, for more than two weeks without incident.

Unlike last year's G4 Cube, which won accolades for its innovative design but failed to win customers because it just wasn't enough computer for the price, the PowerBook G4 should fly off the shelves. Apple's biggest headache with this product should be in keeping up with demand and avoiding the annoying shortages and shipping delays that have plagued the company's most wanted items in the past.

Sure enough, recently reported scattered incidents of orders delayed because of snags in U.S. customs (the PowerBook G4 is manufactured in Taiwan). The problem had better be temporary - Apple can't afford to alienate and/or lose customers who tire of waiting for its products.

The other big hardware news at January's MacWorld was the upgrades to Apple's G4 desktop line. Although they look the same on the outside as the models they replace (the so-called Graphite G4s), the new desktop Macs have vastly improved innards.

Enhancements include a built-in CD-RW drive, a 4x AGP (graphics) port, a fourth PCI slot and a faster system bus (133 MHz). All of this means a good bit more speed and expandability, and a belated nod to the importance of the CD-RW drive long after it had become common in Windows PCs.

While much has been made of the top-of-the-line model with its 733 MHz processor and nifty Pioneer "SuperDrive" that can burn not only CDs but also DVDs - a drive that Jobs said he'd like to put in all Macs eventually - I think the low-end G4 desktops are at least as compelling because of their value for the money.

With a 466 MHz G4 processor - only 34 MHz below the top-of-the-line Mac just a little more than a month ago - the bottom-level $1,699 Mac sports most of the upgrades of its faster, pricier brethren. The main two items it lacks - the more advanced Nvidia graphics card and a faster hard drive - are included along with a 533 MHz processor in the $2,199 model.

Only the iMac portion of Apple's line went without an upgrade this time around, and reports that supplies of several iMac models are not being replenished indicate that a CD-RW drive could be in the line's near-future.

Notice we're talking about CD-RW again. At MacWorld, Jobs admitted that Apple was "late to the party" by not offering CD-RW drives in Macs even as an option.

Evidence of Jobs' newfound devotion to CD-RW technology appeared not just in their inclusion in the new G4 desktop models, but in a new piece of free Apple software called iTunes.

As iMovie has made the editing of digital video on the Mac a breeze, so iTunes simplifies the conversion of songs to MP3 files for burning to CDs. Although the software now only works with the CD-RW drives that come in the new G4 desktops, drivers for third-party CD-RWs are expected to materialize later this year.

Apple's new goal, Jobs said, is to make the Mac the consumer's "digital hub." After having played with both iMovie and iTunes, I can't argue with the man.