Hi Shadow
Its currantly believed that wormholes are made of quantum foam, which consists of a boiling sea of virtual particles constantly appearing and disappearing at the sub-atomic level of space. Within the quantum foam it is believed that its full of wormholes connecting differant parts of space together. They may also connect different parallel worlds or universes together.
The drawback is their very small size, to small for particles to go through. Scientists at Caltech came up with the idea of using a strange type of matter called exotic matter to hold a wormhole open so a machine or device can travel through the wormhole to another point in space or even in time. Another drawback is the energy needed to hold open a wormhole would be extremely high.
The term wormhole has also been used to discribe a possible zone of transition in the centre of a rotating black hole.
Your have a job ordering a wormhole but you can get some good books with info on wormholes, from bookstores, via mail order.
Blackholes and timewarps by Kip S.Thorne.
Has a chapter on wormholes and overcoming the Average Weak Energy Condition (AWEC), etc.
Time: A traveller's guide by Clifford A Pickover.
You can also check out the Stardrive website at
www.stardrive.org. On the main page is a paper on wormholes, timetravel and hyperspace,etc. Its in pdf format.
Tom