I honestly don't do much with the data, in fact I rarely look at it. I do use it to determine sane budgets for various categories of my life, and I sum the entries every few days so I can tell at a glance how close I am to exhausting those budgets. I also find that there's a psychological benefit--when I have to track every purchase I spend less money.

I spend considerably less than an hour a week making these entries, perhaps around 15 minutes. If I was interested in having a more nuanced view of my finances with graphs, &c I'd probably leverage software to save me time.