I'm planning on hooking up my ps3 to my 1080p lcd monitor. So I' buying a hdmi to dvi-d cable. I just want to make sure whether all dvi-d cables support up to 1080 or if different dvi-d cables support different resolutions? Is there a minimum and maximum resolution for these?

They support a minimum of 1080p @ 60fps. http://en.wikipedia.org/wiki/Digital_Visual_Interface
You won't be able to watch blu-ray movies @ 1080p I don't think since it lacks HDCP http://en.wikipedia.org/wiki/HDCP
Although some dvi have hdcp capabilities.

I used a HDMI to DVI cord on my 19" LCD because I couldn't afford to get an HDTV at the time. When I set the PS3 to 1080p, an image actually showed up and the aliasing was pretty good when I played games, so you should be fine.

I just don't understand how 1080p could possibly be interpolated from a 1440x900 resolution

It doesn't. If you view a 1920x1080p source on a non-native 1080p display, what you're looking at is a downscaled, interpolated image.

If you check the output (if the monitor has an info display function) it will most likely show up as 1280x720.

HDCP 1920x1200 monitors are the way to go if you want a smaller display with full 1080p output for games and Blu-Ray.

Nope, when I set the PS3 to 1080p, the "Information" screen which showed the resolution was at 1920x1080. Only at 720p would it show it at 1280x720

Then check your PS3 display settings. It will probably show a check by 1080i, which is how the console outputs signals to non-native 1080 displays.

Either way, it's a crushed signal being displayed on a non-native 1080 display. While it's possible to force a higher resolution on a lower resolution display, it still can't add more actual (non-interpolated) pixels and detail than the display physically has.

disable 1080i and see if it will display, honestly you just have to read about your monitor and see if it is indeed HDCP and what resolutions it supports. I also have a dvi to hdmi cable I use for my ps3 I connect it to my 22 inch spectre monitor all the time seeing as how at the moment I do not have a high def tv.

Hey DTG are you from the US? I know a great site for cables, accessories,etc. I got my HDMI cable from them for $7.35 shipping price included. The quality of the cable is excellent and I while I was looking for VGA to HDMI converter for my Dreamcast, I saw a HDMI-DVI one as well.