When you're on flickr and have decided what pic you want, choose what size you want (i think medium is best). Then scroll down and you'll see :-
2. Grab the photos url . You highlight the link below and right click and choose copy, then go to introduce yourself thread on here do a new thread click, do [IMG] mountain icon [IMG], click on the mountain icon then right click and paste preview post to see if pic is there, then submit post.
Sorry if I have confused you, good luck
Jasper tri 21/Dec/05, Gabby ruby girl 8/Nov/07, and Felix the cat 4/April/10