Yup, absolutely that's the best way. I've found threads on other forums on the internet from 5+ years ago that still have their text but the images are gone. Sometimes those images were crucial to understanding the post. Frequently the image host went out of business, sometimes it's because the poster deleted his account. Either way information is lost forever.
Best to just "upload" images instead of "linking" to them elsewhere for the purpose of embedding the image into a message post. I've seen a lot of message posts look silly at other websites, blogs, forums when the image that was linked too wasn't available any more. Worst, if the message post is old and the person that posted it is still actively posting...he/she doesn't know that old image that was linked too is no longer available. wrbtrader