On a browser, left click on the image, find "copy image address" (or copy image url or some such). It sounds like you are doing this, though. So, maybe you are not getting rid of the "http://" that is already in the dropdown box. Can you put a copy of one of the links in a comment? Actually, I'm not sure how to do that without it trying to link to it. Maybe replace of of the "." with a space or 'dot'.
The other problem may be that the flicker account is private. Maybe you have to set your pictures to "public". This may make sense since you say you can see the pictures. Again, another good reason to post an example link. It would also be very nice for you if this is the case. It would mean that all of your photos would pop up without you having to go through each one and update...
Right! If you look at the link, it's a blogspot link. You would have to set up a blogger account, though, which means a Google account and enable blogger. Photobucket works, also.