Power Point 2 PDF 2 JPG
I just figured this tip out after reading a few posts that didn't tell me how to do this in batch mode. But here it goes. To save or extract images from Power Point save the show as a PDF, you may need the full version of Acrobat. Then in Adobe go to advanced and then extract all images to jpg. It that easy and it maintains most of the image quality. Other sites say you should edit each image in MS Photo Editor but that is one at a time but is suppose to maintain original quality.

DoublePics: Freeware Fuzzy Image Search
If you collect images off the web this is a necessary program. It will allows you to search an entire hard drive for images close to that same. Yes this included different images sizes to remove thumbnails, and even slight changes in the image like facing left and facing right. If the Images are close enough this program will help you find them and then you can save space on you hard drive by deleting the ones you don't need. This program is shareware so the option to delete from within the program is disabled. Now the fix is right click the image and open in a new application, then delete the duplicate. This will take more time but its just a tip. Comparable freeware is D'peg! - The Duplicate Media Manager but its buggy with huge collections, worked best with a few hundred rather than the few thousand that Doublepics was able to take. Also there is Thumbsplus, a payware, has a fuzzy search feature that works only in a folder at a time.