This may not be a revelation to anyone except myself, but Flickr is a really cool service. I remember checking it out early on, when it first came out, and was less than imressed. The interface seemed clunky and at that time I really didn't have much use for a photo sharing site.
Fast forward to today, I now have quite the collection of photos (nowhere near what some people have) and I needed a good way to host them. Typically I would just post them on my webserver but some of these images where just huge. I again looked into Flickr, this time I was very impressed. It's so easy to upload and organize pictures in any resolution. It's also really easy to add neat mouseover regions with popup comments and order prints right from the Flickr interface. Plus Flickr extends to a mini social networking site with lots of other really neat pictures from people all over the world.
I was so impressed with what I saw that I went out and purchased their one-year subscription. For $24 they let you upload 2GB of images per month plus you get an unlimited amount of storage space, which is in and of itself worth the $24/yr.
I would highly reccomend anyone who has any kind of photograph library visit Flickr to start organizing and sharing their pictures. If anyone wants to see my photostream you can check it out here: http://www.flickr.com/photos/mikecrute (I just posted some of the Florida Keys vacation pix).