We've written before about the importance of having a Web presence for your startup, even if you aren't prepared to launch. But a team at this weekend's Startup Weekend in Philadelphia has taken this idea one step further, designing a product that will help startups build viral launch pages: LaunchRock.

LaunchRock is one of those incredibly simple but incredibly awesome ideas. Built by Jameson Detweiler, Dave Drager, and Stephen Gill over the three days of Startup Weekend, LaunchRock makes it incredibly simple to get interested users signed up for your startup service or product, pre-launch.

Of course, any "please give us your email address" option can do that, but LaunchRock makes it incredibly easy for users to share the link to your launch page to friends. Even more importantly, it rewards those users who are most eager - based on the number of friends they invite - by bumping them up the list of those slated to get access to your site.

If you want to see the virality of LaunchRock in action, search Twitter for "Maple Butter," a new project from Flowtown's Dan Martell. And the sign-ups for LaunchRock itself aren't too shabby - over 5000 since the website went live this weekend.

The LaunchRock service gives you the tools to build your launch page - you simply point the A record of your domain to the IP address LaunchRock provides. You'll get a unique URL to share as well as analytics about who and how much sharing is going on.

According to co-founder Jameson Detweiler, "I look at it this way, you manage email marketing campaigns with tools such as Mailchimp and Constant Contact, and you manage support with tools such as GetSatisfaction and Zendesk. Why not a tool that's built to assist in the various vital steps of launching and growing a business?"

The LaunchRock team say that they're planning on adding some additional features, including A/B testing of marketing messages and a LaunchRock widget on your own hosted landing page. But in general, says Detweiler, the focus is helping people "rock" the launch process. "We want to expand on what we're doing here and build tools to help people find their best users and engage them as effectively as possible."