Here is a list of some image storage and album websites, ranked in no particular order:
1. Flickr
This one is probably used by many people, so no introduction is needed. There is a very useful tool that allows you to easily capture the screen, save it as an image, and upload it directly to Flickr.
2. Photobucket
There is a Firefox add-on called ImageBot that makes uploading images to Photobucket much easier and simplifies the process of embedding images.
If you use Flock, it integrates both Photobucket and Flickr.