Builder.com offers this overview of estimating tools and techniques:
http://www.builder.com.com/5100-6315-1045574.html
John Van Gundy
In an article on the Computer.org web called "No More Voodoo Estimating" John Gundy states " Good estimates, based on sound processes, can help a company improve its competitive position. Companies that implement and consistently use strong estimating processes may be able to advance to the next Capability Maturity Model level, and even reduce development costs. A recent study indicates that moving up to the next CMM level can reduce software development costs 4%-11%.* Good estimating processes can improve the quality of decision-making, project control, portfolio management, risk management, change management, and resource management."