It is a great hack I will give it this.
If you could arrange for it to maintain standard image format filenames it would really help integrate it with other image functions within vBulletin. I will uninstall it for the time being, only because my members are confused about this. But I do hope you can change this because this is a very useful and helpful approach to an age old problem.

Great mod you made y2ksw
I like it.

some admins have a limited space to store images in their site, I have some suggestions for future update (if possible)...

add options in ACP to enable/diable:
- signature storage
- storage based on usergroups, users names... this will be excellent for proffesional forums/images describe process by certain members.
- store images in different server/site...because of space limitation. the new location could be owned by same admin.

genius mod, thanks again.

The storage based on forums and/or usergroups has been requested already, but I'm in a sort of stall right now (too many jobs) and cannot concentrate much on adding features.

Storing mages on another server may create many authentication problems, and in the end, if that server is down, the problem of unlinked images reappears again, reason for which this plugin has actually been created :p

Thank for the effoer,

sounds a nice mod...
caching external image..
vb3.6.4 has been released....
its supported by vb 3.6.4 ?
any new feature is coming or any update ?

Sure, it's fully compatible with vBulletin 3.6.4

then shouldn't it be moved into 3.6.4?

Yeah, maybe :p

Still, there are many users of v. 3.5 which can't upgrade because of their server/PHP/MySQL limitations, and this forum is much less crowded than anywhere else.

Let's say, when I assume v. 3.5 is definitively dead, I will ask to move the thread to the 3.6 forums :)

thank you for an awesome mod, is there anywhere I can specify to ignore sig images? or even better, images from the forums domain? we have a default sig for each user that needs to stay updated with stats from game server, stats are based from same domain. being able to turn off cache for same domain would be awesome, thank you.

You may disable the specific plugin for signatures. When diabled, signatures are not considered :)