I installed PMS on a computer of mine that I also use as a web server. I've not got it up and running yet but I'm writing a web script in php to launch PMS. This would allow you to open PMS from the PS3's web browser but the only problem is you would need to have a webserver installed on your PC to make it work. Not exactly the feature that you're looking for but would allow you to lauch PMS without leaving the couch
I'll post back here when I get it done.