A number of these laptop security cables were donated to my local hackspace in Nottingham UK (www.nottinghack.org.uk).
I needed a cable extender for my bike lock, which can be used to lock all the wheels (similar to this kind of lock).
The problem with the laptop security lock is that only one end had a loop. To make it useful I needed a loop on both ends which could not be undone.
So this is the technique I used to create one....
Step 1: Parts Required
Laptop secutiry cable
Section of thick-ish walled steel tube (I used a section from a childs bike frame)
Self-amalgamating tape or large section heatshrink
Hacksaw with metal cutting blade
Large cable crimper (needs to be around 120mm2). This can be either handheld or hydraulic. You will only need this for a minute or so so maybe ask someone who does battery cable lugs?..
Step 2: Cut tube
I cut around 30mm long piece. I was trying to match the other end, but this was a test so I didnt measure it too well....