It looks like today you no longer to have to encode spaces by %20 in your html links or image links. For example, suppose you have this image at ?http://example.com/i/my house.jpg?. Notice the space there. In your html code, you can just do this:

<img src="http://example.com/i/my house.jpg" alt="my house">

It work in all current version of browsers. Though, what i'm not sure is that whether the browser encodes it before requesting the url, or a particular server will do the right with with paths with space? (apache)