I am not sure if it would be possible but I am having a lot of people struggling with imbedding images in their posts using IMG using free services. I assume it is the way these services format their links:

http://f3.yahoofs.com/users/420d2b56z1c421539/a67fre2/__sr_/856cre2.jpg?phAZd.EBfO68jiMd

Anyway around this in how it is handled? I would like for them to use the File Manager built in but most do not even try.

Inline images go through a few checks before they are allowed to be posted. We make sure that they are either a .gif,.png,.jpg or .jpeg before they are converted to an actually img src tag. This is done as a security precaution to try and make sure it's an actual image being posted and not some sort of malicious script.