Tracking down what I spend

When it comes to spending money I never keep track of whatever I spend, when I think of the days when I was in school or college I used to think twice before spending each and every penny.
Today I was discussing the same with one of my collegue who still keeps track of whatever she spends, she suggested me a website named buxfer where in which we can link our account statement and this will generate a proper report of how we spend each and every month.
I m still skeptical whether this will bring anychange in my spending pattern. Should revisit my spending pattern after a month.