|That site uses flash for the download link.|
In firefox you can right click on a download and "copy download link".
.... Which I did resulting in this:
Basically it points to a download script that take the parameters of "key" and "time"
"Key" is the id, also part of the original url. "time" appears to relate to the time the download started, get it wrong and it will redirect back to the download page. There is probably a few minutes grace for the link to work.
You can work out the time yourself. I don't know if it's just seconds or even what timezone it's based on and I don't really want to figure it out either.