## CJam, <s>10</s> 8 bytes

    l2/{)-}%

[Test it here.][1]


### Explanation

    l     e# Read input.
    2/    e# Split into pairs. Odd inputs will yield a single-character string at the end.
    {     e# Map this block over the pairs...
      )-  e#   Remove all copies of the last character from the string. "11" and "00" as
          e#   well as single-character strings will turn into empty strings.
          e#   "10" and "01" will turn into "1" and "0".
    }%

When the list is auto-printed at the end of the program, the empty strings are simply omitted.


 [1]: http://cjam.aditsu.net/#code=l2%2F%7B)-%7D%25&input=1011101010