Using 21.5" iMac for external display?

[macremm]

I know you can use the 27" iMac as a external display cause the Mini Display Port supports input and the 21.5" only supports output, but is there ANY way to somehow convert the output into input? I've researched a bit and read that you can use a Mini Display Port > DVI and then use DVI > HDMI. Is that possible? Oh and if your wondering, I want to use my future iMac as an external display for my PS3, and I don't want to spend $500 more for a 27", I'm already interested on just the 21.5".

 

[Hellhammer]

As far as I know, no, you cannot. There is EyeTV which makes it possible but you're limited to 480p and there will be noticeable lag so not worth it. Invest the money on external monitor which has HDMI port, goes for less than 200 bucks

 

[Jimmery]

I wonder if it's possible to add a software control to give displayport input--I wish Apple would just finish its job and make this work properly. What a waste of form and function to not use that monitor to its potential.