Hi,
where do you want to use the signature?
In the Free-DC forum you would go to "User CP" -> "Edit Signature" and enter
(but without all the spaces I made) and click "Save Signature".[ I M G ] h t t p : / / 4 5 6 3 3 . r a h . s i g . b o i n c . d k ? 1 0 5 [ / I M G ]
To me the URL looks like a redirection, which means that you surf to this URL and you'll get forwarded to another URL (in this case http://www.boinc.dk/auto.php?user=45...39%20-%201.jpg ) providing the information you'd like to see...
EDIT: I had the signatures disabled... now I see you already inserted the sig to the forums...