Locations Tagger is an application for the iPhone.
It is primarily designed to map POIs for OpenStreetMap in a very fast and easy way. You can currently export your POIs via email in a gpx file and edit it with an OSM-editor of your choice.
The App can be installed via the App Store Locations Tagger
Feel free to contact me (User:Law.skynet) if you found some bugs or have some feature requests.