adx is a minimalistic but massively Web-enabled address book that runs completely in your Web browser. It's OS-independent and supports comprehensive details for each contact entry, including user identifiers and profiles for Skype, Twitter, Flickr, Delicious, Facebook, LinkedIn, studiVZ, instant messengers, etc. It supports the hCard and XFN microformats.
phpMyGPX is a Web application based on PHP, MySQL, and OpenLayers to manage photos and GPX files with a browser, on your local machine or online, to share your tracks and images. GPX is an XML file format containing track points and routes collected by GPS receivers, and is very popular with navigation, geocaching, and OpenStreetMap.