Adobe has produced a KnowledgeBase article that includes information about where to find and how to install components previously installed with Photoshop or Photoshop Extended for versions earlier than Photoshop CS4. It also includes information on legacy components that were previously found on the DVD but are no longer included on the Photoshop CS4 discs.

For example:

• Bigger Tiles
• Contact Sheet II
• Extract
• File Formats
• Layer Comps to Web
• Picture Package
• and more!

http://kb.adobe.com/selfservice/viewContent.do?externalId=kb404900&sliceId=1