## Perl, 27 bytes

    say grep{chop$_ ne$_}/../g

Byte added for the `-n` flag.

                         /../g  match groups of two chars
        grep{           }       select/filter on...
             chop$_             remove the last character, mutating the string
                    ne$_        is it different than the remaining character?
    say                         output if so

Test:

    llama@llama:~$ perl -nE 'say grep{chop$_ ne$_}/../g'
    1110
    1
    11000110
    01
    1100011
    0
    00
    
    1
    
    
    
    1101001
    0
    1011101010
    1111