The Fold Doesn't Matter
User Experience and Design, Wed 16th Dec 2009
"Over the last 6 years we’ve watched over 800 user testing sessions between us and on only 3 occasions have we seen the page fold as a barrier to users getting to the content they want."
Browser Size: a tool to see how others view your website
Google Blog, Wed 16th Dec 2009
"On the download page for Google Earth, the install rate increased by 10% when we moved the "Download" button 100 pixels upward."
It may be best to play safe and use Google's new BrowserSize tool