The Internet interprets walled gardens as damage and routes around them. (Unless the Internet is feeling grumpy. Then it just smashes through them.)

Social networks such as Linked In, Orkut, and Friendster have shown the value of being able to search your network of relationships, and control visibility and communication based on degrees of separation.

At the end of the day, though, all of these services are fundamentally walled gardens. Their limited features and scale make them vulnerable to open alternatives.

The social networks want you to take your already existing networks and recreate them in the context of a walled garden which they control and monetize. They seek to reinvent the networks of relationship already manifested online in the web, in people’s address books, in the blogosphere, in mailing lists, and so forth.

Walled gardens survive when there is no open alternative. The open internet and the companies that support it have proved ferociously creative at providing open alternatives when there’s a clear value proposition. Like life, the Internet finds a way.

The internet is learning how to take the social network value proposition and make it apply at scale.

The Foaf Project, an initial attempt at enabling relationship mapping on the open internet, was too geeky and has failed to achieve mass adoption. XFN is a lighter weight standard that attempts to accomplish the same thing using rel tags on hyperlinks, and rides on the momentum of blogs and blogrolls.

Now the big players on the open internet are getting involved in mapping the human internet. Google, for example, is investing in email, blogging, discussion groups, instant messaging, and of course social networking.

At Jobster, our philosophy is that the scale and power of the open internet will win out in the end over walled gardens. We apply this philosophy to the problem of finding better ways to connect companies and hidden talent.

Zdnet reports a growing trend toward mobile search built on top of SMS. For example, 4Info is expected to announce a $7.5M funding round from US ventures. Google has its own SMS service as does Yahoo.

For me, mobile search on a rich device like the Blackberry is an absolutely compelling application. I still need to be convinced about the utility of T9 search on a device with a tiny screen. Let’s assume, though, that SMS search becomes compelling or enough people migrate to richer devices.

The key questions for companies in this space are the revenue model and competitive differentiation. I believe the thinking that has been applied to these questions has been overly constrained by past assumptions about desktop search.

An additional constraint, as always, has been the shortsighted greed of the carriers themselves. I like this quote from an O’Reilly article titled 2005 is Year of Local Mobile Search

The beauty of a application like Berry 411 is that it that allows me to encourage charitable contributions, provide a lot of value to many people with minimal effort, and focus purely on delivering a usable application while sidestepping all of the difficult questions of monetization.

I believe a lot of innovation in mobile devices will bubble up from the grassroots, as in the early days of PCs– if carriers and the data providers don’t kill it.