DokuWiki. If it's just about quickly sharing one page with some pictures, videos, structured text and a descriptive URL, which I also can easily set permissions for outside people, logged-in users, specific groups,... a wiki for me does the job preeeeeeetty well so far. Plus, all my info is already there. Not comparable to all the other solutions mentioned here though, neither feature-wise nor philosophically.

Oh, and DokuWiki uses .txt files for its pages, which can directly be edited from the file system.