event wise it could be fairly simple to get a local copy working, not saying it needs doing, I must be bored
. But customizing the vbulletin save/modify event isn't for everyone.
Code:
user adds/modifies post:
for each img tag
if img url is not em based (begins with http...ecomodder.com)
convert url to filename (uuencode?) and add original extension.
if file doesn't exist
get image data into local filesystem (socket read) using filename
convert filename to EM url (i.e. add appropriate http:// prefix)
use em url for img url
preview can use whatever url is in the message
also, might want to secure the em url path so only logged in users can see pics if bandwidth is an issue.