In the last few days the Google engine in the US has been changed in relation to the impact that Reviews have in Google Places, after one retailer was deliberately horrible to their customers in order to get more reviews logged about their business!
Read The Age article here.
We would never recommend doing anything that is attempting to deliberately trick Google, because they will always make changes to combat that, and you will ultimately suffer.
In an earlier article, Google had commented that they had made on average 2 changes per day to their search engine algorithms (formulas that work out page rank and search results etc) for the first half of 2010.
