Signature picture

Is there any way to use Flickr?
Or do u guys have any suggestion?

Do you mean the head shot on the left or the signature area at the bottom of the post?
For the head shot on the left - no, it is pulled from the lodestone.
For the signature area at the bottom - you should be able to use any url image or other html.

I tried but still not showing... I'm not sure what do I miss here.

Edit: Oh.. it's there.... ok thanks :)