The Google Earth Community, formed in 2002 when Google Earth was still an independent product called "Keyhole", has been an excellent resource for Google Earth users. Not only was the community a great place to post new files that you create/discover, but you could get answers to almost any Google Earth-related question in there.
They even added a Google Earth Community layer to Google Earth back in 2005 to show off the great files that users have added, which you can still find under the [Gallery] section of your Layers.
Recently, the GEC had had some stability issues. Because it was based off of an older BBS technology, it was having increasing amounts of trouble under an ever-growing load. To fix that, Google is now moving it over to a Google Groups-based system which should help with those issues tremendously.
Right now Google is in the process of moving all of the posts and attachments to the new system. With more than 1.2 million posts on there, it'll take some time. They're hoping to have the data ported over by next week, and we'll certainly let you know when it goes live.
If you have any questions or problems in the meantime, you can use the Google Earth forums already in place in Google Groups. For more information about the status of the Google Earth Community, this thread is your best source for information.