Today marks the beginning of Tech Week, the annual pilgrimage to Las Vegas and San Francisco for two trade shows that will feature the gadgets that could capture the world’s attention for the next 12 months.

The International Consumer Electronics Show, celebrating its 40th year, is a vast showcase of everything tech that’s bringing an estimated 140,000 people to the Nevada desert. Macworld is a smaller-scale show that attracts about 40,000 people, mostly Apple-related vendors and Apple aficionados, to San Francisco.

Apple – with its popular iPod, fast-growing online iTunes Store and Mac computer line – continues to grab the attention of mainstream consumers around the globe, while the must-attend mindset surrounding CES continues to prove what a powerful industrial force consumer technology has become.

In San Francisco, the annual keynote speech, which will be delivered by chief executive Steve Jobs on Tuesday, traditionally has been the launching pad for Apple’s coveted new products, the iPod Shuffle, video-capable iPod models and the Mac Mini among them. The company tries to keep its announcements secret until Jobs – who takes to the stage in his trademark black mock turtleneck and blue jeans, sans belt – unveils them.

This year Jobs will almost certainly reveal the shipping version of a wireless device he introduced in September that will link a home computer with the living room TV, allowing people to watch shows and movies downloaded from iTunes on the TV’s big screen.

There’s also buzz that a new iPod cellphone could steal the spotlight. And Mac enthusiasts are expecting a new version of the popular iLife software suite, which includes the iPhoto, iMovie, iDVD and GarageBand programs.

Unlike Macworld, CES generally doesn’t have a single focus so much as many ongoing themes.

Sunday night at a pre-show kickoff, Microsoft Chairman Bill Gates delivered his annual, standing-room-only state-of-the-industry speech.

Microsoft Corp. Chairman Bill Gates demonstrates Microsoft's future mobile technology during the 2007 International Consumer Electronics Show on Sunday in Las Vegas.

His focus this year: ways to link computers and the other hardware people use to play music and movies – and not just handheld devices. For instance, Gates demonstrated a new technology called Sync, to be built into some Ford vehicles, that will allow drivers to transfer music from their cellphones to their car stereos. He also unveiled a new Hewlett-Packard “home server” that will make a music, photo and movie collection available to every PC in the house.

Unlike Macworld, which tends to showcase products that are immediately available for purchase, CES is more about what’s on the horizon – or not. Some products revealed by Gates at CES in years past – such as a Dick Tracy-like smart watch in 2004 – never became must-have gadgets.

Still, for those in the industry, CES functions like a debutante ball for some of the newest and most clever devices. What happens at the show often sets the tone for expectations.

“It’s the annual event where anyone who’s anyone in technology comes to get a glimpse of the future,” said Gary Shapiro, chief executive of the Consumer Electronics Association, which sponsors the event. The show keeps growing in size and importance because now representatives from all the big players in the cable, telecommunications, entertainment and financial industries come to check out what’s happening.

As technology has evolved – with faster Internet speeds, larger hard-drive capacities and smarter computer chips – the lineup of big players at the show has shifted.

Last year, Google made its debut at the show and created a lot of buzz when co-founder Larry Page landed a keynote speech and unveiled its online video store. Google’s video offerings turned out to be somewhat of a flop, but online video itself became the icon of the technology frontier for 2006.

This year, video remains a key player at CES – this time with Leslie Moonves, chief executive of CBS, delivering a keynote speech that is likely to address the network’s push to use the Web for delivery of its programming.