Heap analysis

This is the memory use graph for one of our sites. Does it scream "memory leak" to you? What do I do next to work out what is taking up all of that memory, could it be some sort of harmless Coldfusion caching (I suspect not)?

I like graphs and nice analysis. I don't like sites that go off and sulk without telling me why. More and more I am realising that debugging a site that doesn't break until many people use it is hard unless you have instrumented your system beforehand. You can't just restart it every 5 minutes to put a bit more debugging in, as the people using it get pissed off (Coldfusion taking about 30 seconds to restart doesn't help this).