Phil:
I assumed that posting full size used more of Bob's storage space. If people are logged on, they can click on the picture and see it full size.
Bob: Should I post as full size?
John
It's best to just link to pictures instead of "attaching" them. If they are attached, they are now on our server so thumbnail or full size won't matter.
To link to a picture on the net, copy the URL where the picture is located (right click on the image and click "copy image location) and click the icon above to the left of the smilie, then click the chain link and paste the URL there and then click insert.
This is best with non important pics like jokes, political, etc. For build threads or important things it's best to attach those so they stay.