Hey I've created this handy spreadsheet you can use to keep on top of your PPC campaigns. It helps you set maximum bids and has nice reporting features for daily, weekly, monthly, quarterly, mid year, and yearly profit margins. Check it out: http://www.truewebmoney.com/tools/AdWordsPPC-ROI-Calculator.html Scroll down and there is a download link for the file. Please share your thoughts and opinions!
Liked it so much I created a quick post on my blog about it - http://www.trafficflowseo.com/2009/08/free-ppc-return-on-investment-roi-excel.html Thanks, this is great!