Myspace IS going to open up their API after all.

Well, sorta.
http://developer.myspace.com/Modules/APPs/Pages/Splash.aspx

It's Opensocial http://code.google.com/apis/opensocial/ and your going to need Myspace approval eg audit of your code before they allow it's deployment but it still means (at least for a select few) that, they'll be allowing javascript again.