Hi B.,
We do this with our 4 year old. It works wonderfully, just don't forget to continue to do it! If I'm out of posterboard and forget to make a new chart right away, my daughters attitude is completely different. It's "NO mommy, I don't want too!!!" When I keep the chart Bekah does SO much better helping and she feels so good when rewarded. (I put up a cork board on the back of her bedroom door to display the stars).
After she collects 10 stars she is allowed to use some of her piggybank money and get a "my little pony".
I guess she is "earning back" her pocket money, but I want her to know she can't just have what she wants, she has to earn it by doing small jobs. I'm also starting her early on the value of money, so HOPEFULLY, when she's older she realises money does not grow on trees.
Anyway, good luck, I congratulate you for starting early. There are tones of little jobs a 2 year old can do, and they love to help!