Mac: Apple's Photo Stream service is supposed to be an easy way to share your photos between your Mac and your iOS device, but it doesn't always work as advertised. It's also pretty much only accessible with iPhoto (although workarounds exist), which is pretty obnoxious. MyPhotostream is a lightweight app that gives you access to your Photo Stream without the bloat of iPhoto.
MyPhotostream simply finds the directory on your computer where your photos are stored and then displays them in a very simple browser. From there, you can copy pictures to other services, send them through social networks, or open with an editor. MyPhotostream is read-only, doesn't have any editing features, and doesn't allow you to organise photos inside your folder, but it does give you easy access to your Photo Stream. You can check out a free trial of the app on the developer's site below.