Sony Computer Entertainment Europe has released a set of guidelines in PDF format to assist web developers in creating websites that are compatible with the PSP browser. In addition to this, they have released guides on releasing audio content to be used with RSS syndication.
The guides are completely free with only a simple registration required. You will not get any additional support from Sony, but you can sign up for their mailing list to receive a notification when the newest guides are published.
This is a great source of information for anyone wanting to either develop a new PSP site or convert their existing site to PSP format.
Remember that PGRevolution has a PSP version of our site as well. If accessing it through the PSP browser you will automatically see it, or you can head over to www.pgoz.com and check it out in a regular browser.
Source: PSP Updates