Funny!
I was just writing to you in another thread suggesting you try Dropbox. Great minds think alike

I assume you already have the image uploaded to Dropbox. It needs to be in your PUBLIC folder (as opposed to your photos folder which is private).
On the SCF side, the trick is to use the IMG tags to surround your link
[ img ] http---whatever---.com [ /img ]
Do not put the spaces inside the IMG tags -- I had to put them there to trick the forum into showing them to you instead of "converting" them to an actual image.
KirkS