Continuing the ongoing topic of, the idea of hiding it in plain sight - right in a bank comes to mind. You can easily hide money from an abusive husband bit by bit with the help of a third party.
I recently had a discussion with a woman I knew who recently fled a violent domestic situation, hid out for a while in a shelter and various safe houses while she went through the whole divorce proceedings.
She shared with me a brilliant idea - hiding your money in a bank. She hid her assets from an abusive spouse in a friend's bank.
Assuming there is a legitimate reason to hide your assets, one way you could go about it is to do what she did - slowly withdraw small amounts or $500-$1000 regularly over time, and give this money to a friend who you have to be able to trust 100%.
This third party whom you trust 100% opens an account and gives you the ATM card and PIN number. You make the deposits in cash, thus avoiding a paper trail that someone like an abusive ex or snoop could pick up on to track you down.
It would help as well if you had some kind of excuse as to where the money went - good excuses could include online gambling, or even booking a few red-eye flights to Vegas and renting a hotel (and not gambling). Do this a few times, and there's your alibi.
A family member might make for a trustworthy third party as well. But there are risks, namely if something happened to this person such as an accidental death. That would be a bad scene as once the death notices are filed, the family or attorneys would notify the bank and the account would be frozen.
But, there is a way to indemnify yourself against this scenario by getting the third party to give you a personal cheque drawn on the account. Since (with most banks) cheques are good for anywhere from 3-6 months, you would have to get updated cheques accordingly.
By keeping in regular touch with the third party as well as having a regular interval communication schedule with them, you can keep up on their status and well-being.
If this is someone you trust with your life, say an elderly parent, and they happen to fall off the radar screen for a couple of days, you would have to assume the worst and either withdraw the cash from the ATM or, get the cheque certified and cash it out in a cash-a-cheque store.
This way, you have an insurance plan in case something terrible happens. If it is a family member in whose account you are hiding your money and the worst thing happens, it could also act as a "poor man's will". Money can be easy to hide, after all, its only paper. Something else to consider when you are hiding your money!