If the Web is such an effective dating vehicle, why not also use it to alert the participants of the consequences of hookups gone bad? That's the idea behind inSPOT, which uses short and not so sweet electronic postcards to quickly spread, so to speak, the news that a partner has a sexually transmitted disease (STD).

The San Francisco Department of Public Health (SFDPH) and nonprofit Internet Sexuality Information Services (ISIS), launched inSPOT in 2004 after surveying the Bay Area's gay male community to better understand how, when and if they had notified sexual partners who they had potentially infected with an STD. Researchers report in this week's PLoS Medicine that the majority of men said that they were much more likely to inform serious than casual partners. ISIS and the SFDPH  started inSPOT after concluding that partners would be more willing to fess up if they could do it easily and anonymously. The site gives users a choice of e-cards to send. They take a somewhat humorous tack in an attempt to ease recipients' shock upon receiving one. Among them: "It's not what you brought to the party, it's what you left with," and "Got laid. Was happy. Got tested. Wasn't Healthy."

Each e-card encourages the recipient to get tested for an STD as soon as possible and leaves the sender room should he or she want to include a personal message. The service was so successful with the gay community that ISIS and the SFDPH two years ago began promoting it to the general public. At the site, users can select to send either  "Tell Them"  or "Get Checked" e-cards. The "Tell Them" category gives users the option of six e-cards; they can send the card to as many as six recipients either anonymously or using their own e-mail address. The "Get Checked" section includes STD information, a map of local testing sites, and links to online resources that both senders and recipients may find helpful.

ISIS says that 19 million new STD cases (including 900,000 cases of chlamydia, 330,000 cases of gonorrhea, and 55,400 estimated new HIV infections) are diagnosed in the U.S. annually. The researchers stress that notifying potential sufferers is a crucial step toward preventing new cases.

The researchers report that 30,000-plus people have sent more than 49,500 e-cards since inSPOT began. In 2006 and 2007, 23,594 e-cards went out: 3,631 (15.4%) for gonorrhea, 3,519 (14.9%) for syphilis, 2,203 (9.3%) for HIV, 2,736 (11.6%) for Chlamydia, and 11,505 (48.8%) for  other STDs, including "crabs," scabies; and hepatitis A, B and C. They say that fewer than 10 recipients have reported receiving an e-card in error since the service's inception.

The service is now available in Indianapolis, Philadelphia, Portland, Ore., and several other U.S. cities, and ISIS says that it is coordinating efforts across multiple national agencies to complete the inSPOT portal for all 50 states. The service has already been translated into Romanian and French, by Web sites in Romania and Canada, and ISIS is working on a Spanish-language version. The organization is also interested in gathering data about the proportion of site users who get tested for an STD (as well as whether those tests are positive) as a direct result of receiving an e-card.