hosting static content seperately

Why are some of image tags built using the img,tag and others are 'hard coded'? I can see that some images are part of content returned from javascript functions so maybe they can't use the img.tag.

The reason I ask is that I am hosting static content on a http server that is on a much faster link so I have to modify the img.tag and all of the hard coded image tags. Maybe I will replace all the hard coded image tags with img.tag so I only have to insert the static http server URL in one place?

Also I am using the AOL content delivery network for the javascript files. It seems to work well without firebug enabled but when I have firebug enabled it gives errors.

tag:img is used as a convenience where possible (although it was added after the fact so there may be possible uses where it isn't).

I guess the right thing to do would be to add the static content prefix as an application context value (set in a property file) that would be inserted into URLs as necessary. This could be done for the audio, images, and resources directories. There are probably 500-600 code modifications to make.