RubaRuba is (yet another) new travel web site. But it’s hoping to grow virally by encouraging users to send links to friends through the explosively popular sites Twitter and Facebook. Users can effectively notify their entire list of 400 Facebook friends about your travel experience with one mouse-click.

However, it’s true that most other sites are quickly catching on to this trick, so it’s unclear how much of an edge Ruba has with this feature alone.

Ruba is the latest company of Mike Cassidy, who has consistently churned out successful companies (Stylus, Direct Hit and Xfire, the latter two selling for $532M and $110M respectively). Ruba, based in Silicon Valley (Palo Alto, Calif.) has raised millions of dollars (exact amount undisclosed) from venture capital firms Benchmark Capital and Draper Fisher Jurveston

Ruba offers more than its travel messaging feature, but since this is the age of the tweet, Ruba wants to embellish that. The site hopes the viral exchange of links will lead to more clickthroughs, and thus more activity — and presumably, more advertising.

But if Ruba succeeds, it will do so because of its simplicity and elegance, which it has lots of: If you’re interested in say, France, you click on “France,” and go to a page of user-written guides and reviews about France. These reviews are organized by specific destinations, attractions, hotels, and restaurants. Users submit the reviews (this makes the cost of content production almost zero). The reviews are led by a nice big picture and include a story like “The five best things to do in Paris.”

So far, that’s not very innovative. But next, Ruba bakes in the sharing features on Twitter and Facebook in a more integrated way than other sites. I played around with Ruba, and it’s straightforward — and very fast. The site relies on people clicking around, and so Cassidy hired top engineer Arnaud Weber (he was the technical lead on Google’s Chrome browser project and before that worked at Next and Netscape) to help try to take page loading down to 50 milliseconds. Cassidy says that’s his other advantage over other sites.
Ruba guide page

On the review page, there’s a big button that lets you tweet the review you’re looking at (signs you into Twitter, inserts the URL of the review page into the message, and then lets you tweet). Same for Facebook: Ruba logs you into Facebook immediately, where you can send your friends an update in your activity feed via Facebook Connect.

The site was quietly launched three weeks ago. Cassidy tells me 75 percent of the 10,000 or so people visiting since then have ended up logging into Facebook to share what they’re doing. That’s a huge number.

So for now, Ruba is hoping users will continue to submit guides or collections and keep sharing them — boosting traffic, and ultimately giving it a way to monetize through ads.

Cassidy’s team has been working on the project since last year, conceiving it in the offices of Benchmark Capital, where he’s been an Entrepreneur-in-Residence for the past two years.

Ruba goes up against sites like Trip Advisor, which is a popular review site, but is more text-heavy and less visual, and more focused on reviews than guides. There’s also Trazzler, which is similar — providing pictures and guides, as well as connection to Facebook through Connect.