In view of our housing and credit collapse, should the rules governing appraisals be revised?

Over the past 7 years, I have seen most of my friends, acquaintances and coworkers buy condos or houses, even if they had no income for the value of the condo or house. I have heard that they refinanced houses too because they got more "equity" when houses down the street sold for more, because they got a new appraisal and were given higher value of a loan. In 2003 I looked for a house but did not like what I could afford on standard plans (I did not trust exotic mortgages), and did not feel comfortable with realtors telling me I have to give $20-50,000 more to secure that condo. I am still renting but one day would like to buy. I think to avoid the next collapse (since housing boom and bust is usually cyclical), the rules for appraisals should be revised so that house values do not skyrocket just because a house down the street sold for more, or we will have another bumpy ride in the next decade. Also, is it ethical of the real estate agents urging you to pay more for the house if their commission is based on the total sales price? It is like telling people they want to make more so to give them more money. Please let me know your opinions.