After searching for a while, I came across a couple of ways to do this. The first way is an app called SBSH Historia which you can buy on Blackberry App World for a couple of €€/$$. This looks like a neat app, and very professional, but I didn't need to pay for it in the end as I found a way to do it for free using the Desktop Manager software on my Mac and a Java app called ipddump I found on Google Code.
Here are the instructions for how to do it on a Mac. The Windows procedure is broadly similar.