Data Logger for iPhone

Pachube

Pachube's free Data Logger for the iPhone looks like an interesting app for self-trackers who want to track their weight, calorie consumption, hours of sleep, mood, etc.

Data Logger for iPhone enables you to store and graph any data of your choosing along with a timestamp and geolocation. You might use Data Logger to store electricity meter readings, to create maps of pollution or temperature sensor readings around your neighbourhood, or animal sightings around the city. You can also set up custom data feeds, with user-defined min and max values, tags, description and units.

Data Logger for iPhone (Via Seth Roberts)