Here is a complied list of useful image uploading sites for all of your needs. Topic permission granted by ZephyrShakuraus.
ImageShack - An image uploading site. When finished uploading, copy the last URL, (Direct link to image), and add it to your forums/website.
DneHost - Another image hosting website. Much like ImageShack, it tends to be faster and easier in general to use.
TheImageHosting - Yet another image hosting website.
Photobucket - A popular image storing and uploading site. Unlike the previous, this site allows you to personally stope each image instead o uploading each time. However, it automatically resizes images much smaller than the image uploading sites, so be wary.
