Free ones include Angelfire and Geocities. However, neither one will let you link directly to them for images (i.e. you won't be able to put an image straight into a post here that is hosted on there). Instead, when you upload your picture, also make a simple html page to go with it, and provide a link to that page in your post.
The html page doesn't have to be complex by any means. For showing an image, just open Notepad and put the following into a file:

Change the address inside the quotation marks to reflect the proper one for your image file, and save as an html file.