Flickr

I am liking Flickr's tag function. I have uploaded more pictures now using their upload application, and apart from adding titles and descriptions you can also add tags which lets the same photo belong to many categories.

The best bit about this funtion is the user tags page which lists your tags as different size links depending on the number of images that have that tag applied.

afp australia blandridge brighton bristol cheddar family friends guildford kyle london newyork random scooter sunset vistas