I use the envelope system in the absolutely traditional way: around the first of the month I withdraw the monthly cash for these categories: groceries, eating out, household (toilet paper, cleaning supplies, etc.) entertainment, kids splurge, and "blow." I take it home and split it up - half goes around with me and half stays in the safe until halfway through the month.
It has been HUGELY helpful for us. It is so hard to give people my hard-earned cash that I'm always taking things off the conveyor belt at Target instead of buying them.

We estimate that we're saving at least $500/month in "little" things that we wouldn't have thought about before - hitting Subway on the way home, buying extras at Target, getting the giant sized popcorn at the movies, etc.
Works well for us!