Connect it to your TV and receiver via HDMI, and you can use your TV remote to control the PS3. Not every single function like the BD Remote, but basic navigation. You can also have everything turn on when you turn on one thing, etc. It's the benefit of a Harmony remote without a Harmony Remote. It comes in handy.
I actually bought a Harmony One but, never opened it because of the Bravia Sync between my PS3, my Sony BD player and TV, and my Yamaha Receiver. I actually don't really need it anymore. (anyone want to buy a brand new Harmony One?...I also have the PS3 adapter for it which was used with my 60GB and Harmony 880)