f you have a standalone tristar mx hd pvr recorder, or a hauppage hd pvr, you can use that.
Plug the PS3 (xbox 360 or ds or wii) into the tristar mx hd pvr INPUT ports, and plug the tristar mx hd pvr OUTPUT ports to your TV. Change the input on the hd pvr so you see your PS3 on the TV (this means the signal from the PS3 is going through your tristar mx hd pvr.) Pop in blank micro sd card, flash drive, thumb drive, or just record to the internal hard drive, start your game and hit record on the tristar mx hd pvr.
When you're done, hit stop on the tristar mx hd pvr.
You can now watch the video you just made from hd pvr player by pressing play or put into your PC's by the USB cable and edit it using Microsoft Movie maker, or whatever other video editing tool you have. Once the tristar mx hd pvr is connected to your computer, you can convert it into whatever format you need based on your ultimate purpose (like posting to youtube.). Keep in mind you can also connect it to your computer by a network cable too. Or just burn micro sd card or flash drives all day. You can even make copies for your friends to show off your work. You can do all the copying directly from the tristar mx hd pvr. So need to really use a computer ;)
here is an example of the hd pvr i wrote about:
http://www.newelectronx.com/proddetail.php?prod=tristar-mx-dvr