I bought this to back up my PS3, and it works on the PS3 straight out of the box, no messing around with system formats.
To answer most questions about this Hard Drive regarding movies and such -
You can transfer movies/pictues/songs to this ahrd drive and play them on your PS3, most pictures (Jpeg, Bitmaps, gifs, PNGs, ect) will work, the same for song files too (MP3, WMA, ect) but it can be picky about movie file formats.
I download episodes of LOST and watch them on my PS3 via an external hard drive like this one, they are usually in .avi format, so I know for sure that those work.
With recent firmware updates to the PS3, the variety of formats it can play have been broadened.
But if for some reason you have a format it can't read you can find a PS3 file converter on the internet. They are usually free software that will convert movie files that the PS3 can't play, into ones it can play. They're easy to use, no hassle; its how I got movie files to play on my Wii.
As for the drive itself, its great.
Its deadly silent, really nice to look at and it matches my PS3 perfectly. It has a power-save function, as soon as you unplug it from a device (PC, PS3) it turns off, so it won't be chugging away with nothing plugged in to it.
It comes with software on it for Macs and other stuff, which I won't use, it does come with an icon file, that way when you plug it in you get a little icon version of the drive for your desktop, which is a nice touch.
The AC adaptor is a strange little gadget, it is a typical transformer black box that you'd get with any electronic device such as this, but it comes with inter-changable socket pins, you can slide off the typical British three-pin plug and slide on a two-pin for use internationally. Its nothing I'd ever use but its handy if you travel around.
Overall the price is a steal, get one while you still can!