Paul, I'm sure the floating islands from Canadian ponds is probably an excellent product but I have no first hand knowledge of them.
There was an excellent article on islands in the Nov-Dec 2006 issue of Pond Boss and you can get it from PB.
If the cost of buying one ready made is not a problem then they would be a great addition to your pond.
If you have the time you can also build one using foam noodles, plastic fencing, rigid or flexible PVC, plastic bottles, or even a flat piece of foam with holes drilled into it.
The links that Brettski has provided will give you some ideas of different methods that have been used and you could probably come up with even more.
