Sony Computer Entertainment is opening up new North American applications for its Home closed beta, scheduled for expansion by the end of this month. To get a chance to enter this next phase (assuming you're not already in the closed beta), all you need to do is download the new PlayStation Home theme for your PlayStation 3 over the PlayStation Network. Downloading the theme is essentially submitting your application to join the PlayStation Home Beta test community. PS3 owners who have been spending plenty of time on the PSN will likely have a better chance of being accepted into the expanded closed beta:

We will be using a variety of criteria including activity on the PLAYSTATION Network to determine eligibility for the Beta community. Existing beta testers have automatically qualified to be part of the expanded beta.

Assuming all is according to plan, SCE should open the Home beta to the public later this Fall.