I was standing in a spacious entryway, chatting with the chief science officer at Sun Microsystems. His short-cropped hair, V-neck sweater and glasses were a sure sign of technical prowess.

Peeking just over the horizon, the sun cast a warm glow over a nearby server rack. I was wearing a Sun baseball hat, a T-shirt with the Java logo emblazoned on the front and a purple lapel pin. I was also holding a Sun helium-filled balloon that was at least three times as big as my head.

"Nice facility you have here," I said, as he suddenly vanished into thin air.

"It happens once in a while," said another Sun employee.

In the virtual world of Second Life, anything goes -- even if your goal is to build a corporate brand, hold ad hoc user group meetings, sponsor a conference or help end users find a video card driver.

Here's a list of the top eight sites worth visiting. To find them, just register at SecondLife.com, install, click Search and type the company name to find its island and transport. Save us a T-shirt if you go!

8. Best Buy Geek Squad

Geeks unite! At Geek Squad Island, the most impressive offering -- apart from the bumper car ride that's modeled after the original Geek Squad vehicles -- is deep technical advice.

Real-world employees keep regular hours from 6 p.m. to 3 a.m. and will chat about any topic. I asked about video card support for DX10 games and which USB keydrives work for ReadyBoost, and an agent knew the answers immediately.

According to Diana Garrett, a Geek Squad spokeswoman (and my tour guide), employees will consult for free until a customer needs to buy a product -- for that, they have to call or e-mail.

There are no giveaways, though, and the place is dead during non-working hours.

Note: A search won't work for Geek Squad Island, so use this URL.

7. H&R Block

The wood floors at H&R Block Island (search for "HR Block" on Second Life) are a subtle reminder: This is a top-tier financial consulting portal, modeled after the 12,000 office locations worldwide.

Despite the stuffy decor, there is an interesting point-of-sale angle. For US$100 Linden (the currency in Second Life, which is about $70 in U.S. currency), you can buy the new Tango online tax preparation software. No discount, though -- that was the same price offered on the H&R Block site until a "limited-time offer" was instituted.

The bundle includes access to virtual scooters, dance shoes, a T-shirt and other paraphernalia. Of course, the real transaction takes place on the Web, where you type in an access code.

Unlike Dell Island, where you can build a virtual PC and then buy it online, H&R Block seems to want to conduct real business in Second Life, perhaps as a proof-of-concept. Now that's an innovative spirit!