WeatherTogether.net, a weather community I recently joined as an admin team and folded my weather community blog under, also has a webcams section on the site. We don't have the ability to accept webcams over FTP at the moment, plus we don't have an "official" webcam registration process yet. We are discussing this as a future option and are open to feedback concerning it.
In the meantime, if you're interested in being a regular contributor to WeatherTogether.net and join and create a blog on WeatherTogether.net and also want a link to your webcam featured on the webcams page, let us know. We'd want to do this gradually since we don't have a way to automate the process yet, and we'd be manually doing all the linking.
I'm also going to ask Earth Networks if we have any plans to either roll a personal webcams feature or team up with a site that allows us to ingest in personal webcams. Now that we've sold WeatherBug to GroundTruth and overhauled our executive leadership and tech teams with new personnel, we're in a better position to tackle some new projects, and one is (finally) getting the new PWS system out the door (plus WeatherBug's new owners will have access to the data). We're doing some other stuff with cameras, so I can find out what the interest is there.