Allows confirmation page parameter passing to only pass changed values and lets us pull the values back out to the customer attributes.

gistfile1.rb

# grabs the changed hash and maps it to a flat hash containing just the updated params
@customer.attributes = Hash[*(params[:customer].map{|k,v| [k, v.last]}.flatten)]

gistfile2.rb

# just pass the changed parameters to the controller. note, this page is form-less. 
# simply passing parameters via 'get'. Not sure this is a good idea.
<%= link_to "Confirm Changes", {:action => "confirm", :customer => @customer.changes} %>