Ruby object filtering in arrays

gistfile1.rb

my_data = [
  {
    :foo => 1
    #etc
  },
  {
    :foo => 2
    #etc
  },
  {
    :foo => 1 #duplicate property, should be removed
    #etc
  }
]

# how would I write some code to go through this array, and remove any objects that have a foo property the same as a previous object in the array?

my_data.uniq { |h| h[:foo] }