We use
www.mylunchmoney.com
, too. I have a couple of minor issues with it, but generally think it's great. They only show a week's worth of history, so I have to remember to go in and religiously check it every week, or the history is gone. In our school, the kids enter a PIN number to charge their lunches against their account, so I mostly use it to check and make sure no one is punching in one of my kids' numbers. And also to monitor how many Otis Spunkmeyer cookies the kids are adding to their lunches!
I have 4 kids on the system from kindergarten through high school, so once one kid's balance hits below a certain amount I specify, I get an email. Then I look at all the kids' balances at once and refill them all at the same time. That way, even though I am funding 4 kids, it is still one transaction, so I only get hit with the $1.95 processing fee once. The maximum you can add to any one account was reduced this year down to $100 from $150 at the beginning of last year; I kind of wish it was higher.
As much as I like it, and I have a lot of friends who also love it, I'm not sure how many parents actually use it. We've had it for almost 2 years now, and I still talk to a lot of parents who claim to have never heard of it!