What are some valid ways to obfuscate the scriptPubKey? Is it possible to hide the balance of an address from standard clients who may be watching blockchain?

I'm thinking about using script to modify the the key that is to be verified, but am having trouble concocting such a script.

Is there any prior work that does obfuscate the RIPE160 address?
You can insert two OP_HASH160 after the OP_DUP and then push the hash of your pubKeyHash. Nobody can tell the recipient address this way.

Example:

OP_DUP OP_HASH160 OP_HASH160 double_double_hash OP_EQUALVERIFY OP_CHECKSIG 


Where

double_double_hash = RIPEMD160(SHA256(RIPEMD160(SHA256(pubKey))))