You could buy a USB addon card to display your PS3 on your laptop, but quality won't be that great.
The problem with any converter for video, like Schnitter states for the USB addon card, is the visual quality will take a hit. Cheaper products equal lower quality output, so plan accordingly. I used a component input a few years ago in Afghanistan with my PS3 b/c I did not want to invest in a tv, and although the quality was less than stellar, it was enough for me. If it ever comes to you playing on your laptop screen, chances are quality will not matter for the small time you are on it. If you are thinking long-term for the video feed, do your homework and find one with good quality output; these will also allow you to record your gameplay to post on YouTube and such... a little research will yield you what you are looking for, it is possible, you just need to find what you want/need to accomplish and work from there.