Official Ruby Inspector
Ruby 2.0, 69 bytes

#!ruby -Kn0rdigest
p'&#xd7;&#xf1;F&lt;&#x1f;&#xec;X&#x82;&#xc9;&#xb2;&#x9f;_&#x2;'.index Digest::MD5.digest(gets)[0]


Hexdump (to faithfully show the binary data in the string):

00000000  23 21 72 75 62 79 20 2d  4b 6e 30 72 64 69 67 65  |#!ruby -Kn0rdige|
00000010  73 74 0a 70 27 d7 f1 46  3c 1f ec 58 82 c9 b2 9f  |st.p'..F&lt;..X....|
00000020  5f 02 27 2e 69 6e 64 65  78 20 44 69 67 65 73 74  |_.'.index Digest|
00000030  3a 3a 4d 44 35 2e 64 69  67 65 73 74 28 67 65 74  |::MD5.digest(get|
00000040  73 29 5b 30 5d                                    |s)[0]|


Explanation:


The -Kn option reads the source file as ASCII-8BIT (binary).
The -0 option allows gets to read in the whole input (and not just one line).
The -rdigest option loads the digest module, which provides Digest::MD5.
The code then does an MD5 of the input, takes the first byte of the digest, and gets its index in the given binary string.