This snippet from one of the links:
U.S. and allied authorities are still tracking merchant ships believed to be owned or controlled by Osama bin Laden and his worldwide al-Qaeda terrorist network or their sympathizers. Officials said the ships can be used to smuggle terrorists, explosives and other arms--including chemical, biological, and crude nuclear weapons. The ships are also said to have helped finance al-Qaeda and to move heroin manufactured in Afghanistan to transshipment points for Western distribution. The officials also said bin Laden, who may have fled Afghanistan in mid-December under heavy fire from the U.S. and its Afghan allies, could attempt to escape the region aboard one of the vessels. According to recent media reports, Norwegian intelligence sources have furnished the U.S. and the North Atlantic Treaty Organization with a list of 23 cargo ships linked to bin Laden and al-Qaeda. The ships' names, listed owners, likely cargoes, and flag states remained classified Jan. 1.
It is now known OBL has 28
A Yahoo search turned up these:
From UK Guardian (a great source):
Twenty ships have been linked to bin Laden - and any one of them could be sailing towards our shores
'It could make a terrible mess of a city and would be relatively easy to do,' said David Cockcroft, general secretary of the International Transport Workers Federation. 'It is perfectly possible and there are clearly people who want to do it.'
Article is chock full of amazing details:
Interesting links state 15 belonging to OBL and AlQ, work its way up to 20+ and now being reported as 28