How to use my display as external for PC?

Here is a cable, but I don't know if it will work for what you want:

http://www.monoprice.com/products/product.asp?cid=102&cp_id=10246&cs_id=1024604&pid=5998&seq=1&format=2

They have different lengths.

glor

I was looking into connecting a Powermac G4 that has DVI out to a new iMac also. A suggestion I got on the Macrumors forums was this http://www.atlona.com/Atlona-DVI-to-Mini-DisplayPort-Converter-p-17859.html
At $149 I might go for the MacPro option than an iMac.

That is the only alternative. You need a converter, which the Atlona product is, not an adapter, like the cable Glor pointed to above. Plus that cable Glor linked only works in one direction, it is a mini-DisplayPort to DVI adapter cable to connect the iMac to a second display with DVI input.

The issue that you will run into with the Atlona converter, is that the resolution that you get will be half the iMac's display's native resolution, 1280 x 720. If you need to drive the iMac's display at its full resolution you need a scaler. Atlona makes an HDMI to m-DP scaler, but it is US$279. It has been on sale through TigerDirect for $199.
http://www.atlona.com/ATLONA-HDMI-MINI-DISPLAYPORT-TO-MINI-DISPLAYPORT-SCALER-AN D-SWITCHER.html
http://www.tigerdirect.com/applications/searchtools/item-Details.asp?EdpNo=64335 82&sku=A85-1270&srkey=AT-HD620
But you will need a DVI male to HDMI male adapter.

A better bet, and much less expensive if you can do it with your PC, would be to switch your PC's video card to one with DisplayPort video output. Then a simple DisplayPort to mini-DisplayPort cable will allow the PC to drive the iMac's display at full native resolution.
http://www.pricewatch.com/gallery/video_cards/displayport


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