LONDON

Plugged in: It may be dark, rainy, and ancient, but London (view slideshow) is packed with one of the highest-paid, best-educated workforces in the world. As a result, it's rated as one of the best cities in Europe for tech start-ups—not least because London, which has always been a finance hub of Europe, has the continent's most established venture capital community.

Homeport: There's no shortage of fancy boutique hotels in London, but the Zetter (view slideshow), in hip Clerkenwell, is one of the better, more affordable ones. High-tech features include an interactive TV with 4,000 MP3s on demand; it's also super-green—the AC uses water from the hotel's own well, and when it's hot, skylights automatically pop open to vent air. And though it's in a converted 19th-century warehouse, the Zetter has an Austin Powers sensibility: Every room has a "porno pink" lighting option. The vending machines sell Champagne, gin and tonics—and cameras, you animal.

Social networking: London's leisure proprietors are obsessed with high-tech geekery. The Asian-fusion menu at Inamo (pictured above) is beamed down onto your place setting from overhead. (If that seems gimmicky, think of the business benefits: fewer waiters, faster food=more money.) At 24:London, you summon the bartender via the touch-sensitive bar, and the walls are adorned with rotating projections such as deserts and waves.

When to interface: In 2008, Mashed expanded from a Yahoo! employee freak-out to a geek-community olympics. The weekend starts with a lineup of technologists showing off their projects and culminates in a fevered, 24-hour coding session with 200 teams competing to build the coolest applications. Last year's winners included an application for tying Lonely Planet recommendations into online maps, and an RSS feed system for your TV screen. If you're looking to cadge a brilliant new idea, this would be the place.

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