I have been watching
http://icasualties.org for the past year and a half and they have done an outstanding job of documenting the casualty and death figures from Iraq.
Yes, they use reports from the media and DoD to compile their information, but they always go back and cross-reference them with local newspaper articles.
If 4500 Americans were dead in Iraq and not listed on the DoD website, we would be hearing from their families. Promoting this idea that the figures are wildly disparate from what is being reported detracts from those who have suffered and makes those of us who oppose this war look like people uninterested in the truth.