I have an old but very good 20" imac. Has a Penryn core2Duo. I used to do some webdesign stuff and going get back into it now I bought CS3 for mac. But my secondary monitor from my old gaming PC just not good enough. I got it hooked up to my mac but the mac screen res just blows it out the water. If I moved stuff from mac screen to the 18.5" external it just HUGE. not really usable. So I went hunting for a cinema screen seen how good they look and same res as my imac so thing should not look so huge. I found a 2009 20" for £29.99 inc shipping. I'm pretty happy with that. OK it has a mark down the screen but can live with that as it a 2nd monitor. also has bonus of usb hub as my mac only has 3 ports.