PowerPoint makes it easy to produce professional looking graphics quickly. Sometimes I need to export high quality versions of those slides. By default, PowerPoint limits exports to a resolution of 96 DPI (by comparison, many printers use 300 DPI). However, it is possible to change the default DPI by creating a registry entry.

For Office 2007, browser to
HKEY_CURRENT_USERSoftwareMicrosoftOffice12.0PowerPointOptions

And create a new DWORD value called ExportBitmapResolution. Finally set the value to the DPI you want, e.g., 300.

Now you can export high quality slides by saving them as images.

Instructions for Office 2003 and a list of DPI values and their corresponding image sizes is available at http://support.microsoft.com/kb/827745