HOW can i RECORD/SAVE my PS3 gameplay?

Firstly, the PS3 can only output either AV OR HDMI, not both at the same time. Secondly, you need to decide on quality. If you want to record in full HDTV 1080p then you will need something like a blackmagic capture card. If you just want to put your videos on youtube then a standard video capture card or a Dazzle will work. I don't know how upgradable your IMAC is (I'm waiting for my friend to come around so I can strip his one down) you may have to use a usb device if there are no internal slots available and this restricts the quality (I have not found a HDMI USB Capture device yet).

When you've got the capture device you want, it is then just a matter of connecting the wires up and viewing the game on the computer. You could use a splitter and view the game on the TV also.

I had a quick play with setting up a camcorder on a tripod. It's a bit crude but it saves alot of mucking around and the quality isn't too bad. I don't know the speed of my HDTV but it's fast enough that I don't get the anoying flicker or other problems that you get with old TVs

get the dazzle capture card. :D

its $100 bucks for a mac version i think

$50 if u have a pc.

you should run bootcamp/parrelles for it to be $50 bucks.

im trying to do the same thing with my 360