Thanks guy. But that's just a fancy interface for looking at a process list in an ssh prompt. What it does it just show active queries at that particular moment in time; as I said above, the slow queries are random and sporadic. To look at the process list at the exact moment a slow query is running would be near impossible.
I've since read about a mySQL option that will create a log of slow queries. Has anyone had any experience in using that to know of it's useful?