Imac as External Display

I think I already know the answer to this question but feel compelled to ask nonetheless.

So I have a 20 inch Imac with a bad motherboard, its fried, and I have a 27 inch Imac coming in the mail. I am wondering if it is possible to use the 20 inch computer as an external display somehow even though it wont boot. Theoretically it seems like I should, the display is still good, just the CPU is bad. But I believe many of you will tell me this is not possible...

So whats the verdict? Also, other than a paperweight do any of you have suggestions for me who hates to see his old baby go and wants to do more with it than throw it away? I'm already putting the old hard drive in an external enclosure.