linux t-shirts here :
http://www.chennailug.org/ . not many . mugs might be available online at sify or rediff shop online . Gnurag , has a HUGE tuxian teddy .i am sure he is too attached to that one to sell that piece
, but he might give u directions on where to purchase thats ones siblings or clones .
for the wild ones : i suggest being in true spirit of linux , take a plain cap and get those camlin or other brand colours and start writing ur own captions and drawings on the cap .