TagIt will soon be releasing a public alpha of TagIt Key IT symmetric block cipher.
Program will encrypt private keys with md5~sha/password/salt/16b vector/Bump iterations/128-256b keysize then place them inside of an image of your desire.
Encryption should be strong enough to put pictures with private keys right on your facebook page/twitter.
There are over 600 BILLION images added online every year. Makes a good place to hide.