Well, that is the simple, yet sensible, concept behind QiGO, a key-shaped USB device that links you instantly to a specific Web site when it is inserted in your computer. The applications for the keys–from being able to create safe kids’ sites to creating fan sites for artists to visiting paid adult pages without a trace–are endless.

By way of background, D: All Things Digital, the annual tech and media conference Walt Mossberg and I host, has been sold out with a long wait list every year we have put it on.

That has meant only a few hundred people can see the interviews and also demos we do live onstage with some of the tech and media industry’s most interesting and important players and products.

The lineups have included Microsoft’s Bill Gates and Apple’s Steve Jobs, as well as Eric Schmidt of Google, IAC’s Barry Diller, Meg Whitman of eBay, Cisco’s John Chambers and many others.

And we’ve demoed stuff like the Treo when it first came out, as well as digital toilets, Wi-Fi phones and much more.

We usually post the photos and videos of the interviews and demos six or more months after they take place on a separate conference site. This year, our Digital Daily’s John Paczkowski liveblogged D5 and also posted video highlights from all of the sessions immediately on our newly launched site here.

Now, we are posting videos of every session of the 2007 conference here, in full, and we have made all our photo galleries, hosted by SmugMug and mostly shot by our fabulous Asa Mathat, public too. You can also access our videos via the site’s master player here.

Every day, I am going to highlight a different interview or demo from the conference.

Today, it is our QiGO demo, a product I like for its simplicity and ease of use and that it aims for non-techie audiences (its creators have also invented hit toys, so this is no surprise):

Everything goes on the keylike device’s memory, billed as being smart (for connecting users to a predetermined online destination), secure (for linking users to predetermined, private content) and dynamic (because an infinite amount of content can be unlocked without taxing the memory of the QiGO device).

“Our goal was to make the Internet tangible and intuitive while eliminating user names, passwords and PINs,” said Dan Klitsner, co-founder of QiGO.

QiGO technology has already been used with Konami’s online trading-card game, Yu-Gi-Oh, as well as Hasbro’s Net Jet online game system. It has also been licensed to Fisher Price for use in preschool toys that will connect children to gated versions of existing children’s Web sites.

QiGO keys will be available to consumers this fall.

For kids, they have different uses (e.g., the so-called walled garden, where underage children cannot access the Internet but can still play computer games). For adults, it makes possible premium Internet experiences (such as a year subscription to The Wall Street Journal). Could people also use them to access porn sites? Kara asks. “We never thought of that,” Klitsner replies.

Potential users can load the device with photos and visual memorabilia, then offer the QiGO as a gift, for instance. As an early Father’s Day present, Walt got a QiGO with pictures of his sons. Kara also received one with photos of her sons.