It wasnt unhelpful, you wanted to know where the images displayed....you can just open the png file in paint and scribble over the bars in different colours and then upload it and look for each colour

. There are HEAPS of programs that open PSD files, and GIMP opens them fine, or it does for me.
http://www.raymond.cc/blog/how-to-open-psd-extension-files-without-installing-adobe-photoshop/My comment was not unhelpful, just scribble on each of the thingies with a different colour and then save and look around your forum and make note of where each one goes. Which was my original suggestion - and would surely have solved your problem?
On cost I can understand that. Photoshop is also announcing (or maybe already announced) their new suite is going to be $50 a month, which when worked out saves you over $1000...while that's savings I cannot afford that. If you're a student you can get it for about $150 or so....If you're a student google "student software". They have massive discounts in all major countries because they wanted to stop students pirating the software (another option for you). I bought Design Premium for $435 or something. And I'm using a trial for Lightroom which I wish came with it because it's flippin fantastic! lol
If you want help with sprites (I lote them), just get the co-ordinates from the css (or by using Firebug to select the image in your browser) and in what ever program you use you can either make two guides and find where they meet, or you can make a selection of the size and stick it in the top left corner. I suck at explaining so I hope that makes sense to you lol.