Is "6 bit packed ASCII" an effective encoding to obscure text data? I wrote a routine for a former employer that took the low six bits of ASCII text and "compressed" by cramming the bits together, so that 4 bytes reduced to 3. This had the advantage of automatically folding lowercase to uppercase (not reversibly) with no computational effort. (Our text data was supposed to be just upper case letters, digits and punctuation. Can you say COBOL? I knew you could.) Note that I also ignored the first 32 ASCII characters as well. (They did not appear in the input data.)

Would this encoding method obfuscate text (where SHOUTING was acceptable) in a way that does not yield readily to simple analysis? The data would be encoded from 4 bytes down to 3 like this - (assume that we are only looking at the low 6 bits of every byte, the high 2 bits are just clipped off):  

B1 = all 6 bits of first byte + low 2 bits of 2nd byte  
B2 = "upper" 4 bits of 2nd byte + lower 4 bits of 3rd byte  
B3 = last 2 bits of 3rd byte + all 6 bits of 4th byte  


(Is there a prettier picture to illustrate this?)
No. I actually new how to do such coding on my MSX machine in the mid-eighties (when I was 12). I'm pretty sure I could have decoded it back then. Note that binary code was much more used at that time; you had to code in assembler to get any kind of performance. It was also pretty common to compress things in such a way because you did not have much memory either.

What you're describing is an encoding scheme. Encoding is something different from encryption. Obviously it can obfuscate text, but that obfuscation is just skin deep. This is especially the case if somebody starts to look for strings.

You could however encode to base64 with a different alphabet. That kind of obfuscate things enough that you have to revert the encoding to read it. You could also XOR your scheme with a (multi-)byte pattern to make things less readable for humans.