Too few calories

I need to start some sort of food log. I realized yesterday at dinner time that, once again, I was way under the amount of calories I should have had for the day – to the tune of not even breaking 1000. So I had extra helpings of dinner, but then I was full and didn’t want to eat any more. I think I had 1,100 calories, maximum. It wasn’t because I was turned off by food or anything, like last time; it was just that I plumb forgot to eat. Such a winner, I am.

What do you guys think about online programs like SparkPeople? Is there a better one?

EDIT: Giving it a go.