One of them that i like is called the Humdinga(Gibbs Technologies):
http://editorial.autos.msn.com/article.aspx?cp-documentid=434464
The Humdinga was designed for military use, offering four-wheel drive as well as the ability to move at 40 mph on the water.
Equally versatile on land and water, the Humdinga can carry five passengers at up to 100 mph on land.
http://www.gibbstech.com/humdinga.php
Although the new application utilizes the same patented HSA technological platform as the Aquada, it shares no common component parts or systems with its predecessor. It has been designed specifically to access remote and hostile terrain. The Humdinga can comfortably transport five people complete with luggage/supplies on at least twice as much of the world’s surface as previous vehicles.
The Humdinga illustrates the scalability and versatility of HSA technology. HSA Technology can make vehicles ranging from passenger cars to SUVs to buses and trucks High Speed Amphibians.
The Humdinga transforms from land to water mode at a touch of a button. The wheels retract, the power train switches from the wheels to a jet propulsion system and the vehicle is in amphibious mode. In just a few seconds the driver is planing at a speed of forty miles per hour.
"This 4WD HSA demonstrates that the technology is adaptable for a whole range of applications. It took us 8 years, a million man-hours and tens of millions of pounds to develop HSA technology. With this latest vehicle, I'm sure that the technology's potential is clear for all to see.", comments Alan Gibbs, founder of Gibbs Technologies.
On land the Humdinga can accelerate from 0-60 in 9.2 seconds and on water can reach the 'plane' in less than 10 seconds. It has a curb weight of 2000kg, has all wheel independent air suspension and runs on regular unleaded petrol. The vehicle is 5400mm in length, 1850mm in height and 2000mm in width.