For the XMPP interface for the Stack Overflow chat, I am currently taking the HTML of the chat messages and converting to valid XML, and setting that as the html
ch
Just an idea...
What about parsing the image URL's, downloading the images, putting them into a temp folder with filenames representative of the original URLs (the filename could be a hash of the original URL) and substituting the original URLs in the messages for these file URLs?
Another idea... having a local server that fetches the real URLs?