The bookkeeping isn’s as bad as I thought it would be. I have a Google Docs spreadsheet set up with all the categories and I simply update the totals as I spend throughout the day using my iPhone or on my laptop.
I think it’s the daily updating that makes it easy. I only spend a few minutes total each day, and now it’s just a habit to keep track of stuff in my head until I can update the category. 🙂