GoodGuide was one of our favorite start-ups launched at the TechCrunch50 show back in September. It was also one of the few companies in the mix with a local search business model (see write-up here).

This week, the company took top honors at a “launchpad” competition of start-ups at the Web 2.0 summit. It went up against five other companies (including Everyscape, a mapping company we’ve followed).

The company also launched an iPhone app this week, as promised, which takes its product search features on the go. The app includes the ability to browse and search the site’s database of 60,000 product SKUs, and review their health, environmental and social “performance.”

Like a lot of local search sites, the launch of a free iPhone app should augment its value proposition, use cases and marketing. On the latter note, look at UrbanSpoon, a previously unknown company that has been put on the map (no pun) by its very popular free iPhone app: It now has its own Apple TV ad, and is the third most popular free app in the App store.

Back to GoodGuide, it will be a company to watch. And we’ll do just that.