Flickr
Flickr is a popular photo sharing web site. Since you can use it to store photos, you can also use it as a self-tracking tool if you want to use photographs as your data points. For example, you can take pictures of your daily meals or your daily activities. You can also use Flickr as a memory bank of significant events that you take pictures of. Flickr is free, but your space is limited. You can pay the annual fee of $25 to store an unlimited number of pictures.