The application/website is asking for authorization from me- will it reveal my Flickr/Yahoo! password?
No. The authorization is a process in which the application you want to use will send you to the Flickr.com website to ask for permission. There will be a paragraph that explains that the application wants your permission to change various things in conjunction with your Flickr account. Different applications ask for different levels of permissions depending on what they do. Some types of changes are: • Showing you your private photos • Edit and delete photo metadata like tags • Read and write permissions to your photostream You are given an option to grant permission, or just continue browsing on Flickr if you choose not to. Your password is not sent to the third party application or website, there is an exchange of information between Flickr and that application that you have granted permission to allow the changes that the application is designed to do. After clicking the blue button, you then return to the third party application to use it.