This app performs a lot of the quick edits that you may need to do on a photo -like removing red-eye, or converting a file format from one to another. The feature which impresses me most, and that I used often, is it's screen capture utility.
Best of all, of course, it's free to use for personal use.

As most of you are already aware... Apples Quicktime player restricts some of it's features in the free version and taunts you to purchase the pro version. This handy program performs similiar to Quicktime Pro and best of all (of course) it's free. I've been using it for years and have no regrets. Here's a direct link to the download page: http://www.free-codecs.com/download/QuickTime_Alternative.htm

Do you have a file that you can't open and/or view?
Try out Irfanview, it's a desktop program designed to do just that. It's free (for non-commercial use) and easy to use. Check it out at Irfanview.com.