I have another forum with the same set of rules that don't allow you to post huge pictures on the forum using up the hard drive space on my server. The software allows you to take a 15 megapixel photo that might be 66 inches tall and shrink it down slightly smaller then your monitor and further shrink it's bytes down to about 60k by removing information the monitor doesn't need to show a good picture.
http://www.findmall.com/read.php?86,1868270,1868270#msg-1868270
You'll find a good discussion on what others do to post pictures on my other treasure hunting website. That site has about 35 million visitors so you'll get good information from some of the regulars and if you don't watch it you'll find yourself buying a metal detector.
Thanks..
G..
