What makes a good tester

Check out the following writeups by experts on the topic 'what makes a good tester':

By Boris Beizer: http://www.sqatester.com/qateam/qualitiesofagoodtester.htm
By Joel Spolsky: http://www.joelonsoftware.com/articles/fog0000000014.html
By Harry Robinson: http://www.stickyminds.com/sitewide.asp?ObjectId=7815&Function=DETAILBROWSE&ObjectType=COL
By Rob Davis: http://www.robdavispe.com/free/index2.html  
By Michael Hunter: http://blogs.msdn.com/micahel/archive/2004/06/09/151778.aspx

Others:
http://blogs.msdn.com/chappell/archive/2004/03/26/97003.aspx
http://www.globaltester.com/sp5/tester.html