PPTools
Shape Styles brings the power of styles to PowerPoint. Apply complex formatting with a single click
Merge Excel, CSV or tab-delimited data into PowerPoint presentations to create certificates, awards presentations, personalized presentations and more
FixLinks prevents broken links when you distribute PowerPoint presentations
Optimizer saves disk space and bandwidth, shrinks your PowerPoint presentations to the right size for email, screenshow or printing
PPT2HTML gives you full control of PowerPoint HTML output, helps meet Section 508 accessibility requirements
Prep4PDF preserves interactivity in PowerPoint presentations when you convert to PDF
Image Export converts PowerPoint slides to JPG, PNG, GIF, WMF and more
Photos
There are dozens of companies that provide images either free or on a royalty basis. A Google search on terms like "stock photo" should get you plenty of links to follow up.
Fotosearch Stock Photography Search is one site where you can search for commercial stock images.
awesome graphics for PowerPoint
Search terms:stock,photo,image,picture