I could make a long argument, but many others already have for me. Please visit their web sites for in depth analysis on why the metric system is the only logical choice for the US!
http://www.metric4us.com/whynot.html
http://www.createdebate.com/debate/show/Should_the_United_States_convert...
http://answers.yahoo.com/question/index?qid=20080624193751AA0aNiI
http://www.wisegeek.org/why-does-the-us-have-a-different-measurement-sys...