You can use it to find anomalies in data sets. I'd read somewhere that Starbucks coffee prices stick out on financial audits using benfords law, because they're over represented.

In my scenario, I simply had access to a massive data set of hard drive sector failure LBAs, and had just read about benford's law on Slashdot (back in the day), and was skeptical that benford's law would actually fit this data.... so I tried it. And the data fit benford's law perfectly - with a single digit. When I tried it with 2 digits, and again, it fit perfectly - except there were two spikes which stood out. Curious, I started digging in... it was an interesting failure mode.