Uploading photos to web sharing sites — as fast as you can take pictures — is kind of a new obssession for the digerati. Eye-Fi is riding that wave with memory cards that have built-in Wi-Fi antennae that can upload photos to photo-sharing sites.

The Mountain View, Calif.-based company has raised $11 million in a second round of funding. The lead investors include Translink Capital and LMS Capital. Existing investors Opus Capital and Shasta Ventures also participated. To date, Eye-Fi has raised $17.5 million. The VCs note that the service is dead simple; you just take photos and they’re automatically uploaded to a service of your choice.

Jef Holove, chief executive of Eye-Fi, said that customers have uploaded more than three million photos to photo-sharing sites since the company launched its memory cards in October 2007. Holove said the company will use the money for product development as well as international expansion. Translink has expertise in Asian markets, while LMS focuses on Europe. That is why Eye-Fi chose to work with them.

“We were also looking for someone who understood consumer devices and had experience in businesses that combined services and devices,” Holove said.

Holove said that the economic environment isn’t good for raising money now, but he said it isn’t so bad for companies with solid execution. Eye-Fi products have been a success because they can upload to a variety of photo services, such as Flickr or Kodak’s site. Many of the cameras with built-in Wi-Fi services — from companies such as Kodak, Nikon, Sony and Panasonic — can only upload to one site. And while surveys confirm that users want to upload from cameras directly to the Internet, fewer than 1 percent of digital cameras have Wi-Fi capability.

The Eye-Fi card uses a tiny Wi-Fi networking chip from Atheros Communications. Wireless networking chips are so advanced that Atheros can essentially put an entire Wi-Fi 802.11g radio on a single chip.

The Home version of the Eye-Fi card sells for $79. That one can upload pictures wirelessly to a computer. The $99 Share version can upload pictures to web sites from a home Wi-Fi connection, while the $129 Explore version can upload from any Wi-Fi hot spot. The Explore version can also geo-tag the pictures, or put location information into the picture.

Eye-Fi was founded in the summer of 2005. Since the launch, the company has formed partnerships with Nikon, Lexar and more than 20 online photo destinations; and expanded its online and brick-and-mortar retail distribution to include national chains such as Circuit City.