Bob can answer better than I but I think all this is, is a link to a picture/chart (where the chart happens to be a picture of augie's dog :). So I think only a link to the chart is stored with the message on Bob's servers which doesn't take any space at all. But that's JMHO.
Zeev, signature pics don't take any space at all on iHub, because iHub does not offer storage -- except for the text of posts and such.
All graphics, whether charts or pictures, have to be stored somewhere other than iHub, (since iHub does not offer storage). I keep mine on a friend's free webspace that she gets with her internet service.
As far as bandwidth usage, they are pretty small graphics, so they don't take much. Plus, a browser will only pull a graphic up fresh the first time it "sees" it. After that, it will look for it on its own hard drive in the browser cache.
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