To simplify this expression, we can start by multiplying the numerators together and the denominators together:

(1 + 1/2005) x (1 + 1/2006) x (1 + 1/2007) x (1 + 1/2008) x (1 + 1/2009)

= [(2005 + 1)/2005] x [(2006 + 1)/2006] x [(2007 + 1)/2007] x [(2008 + 1)/2008] x [(2009 + 1)/2009]

= (2006/2005) x (2007/2006) x (2008/2007) x (2009/2008) x (2010/2009)

= (2010/2005)

= 402/401

Therefore, the simplified expression is 402/401.