One sort of proxy would be to contribute to an IRA for them once they reach working age (16)--as long as they have some income you could put in just about 100% of what they make. If you put away $25,000 for a kid by the time they reach 21 in their IRA, if you assumed 10% return per year, it would be worth almost $1 million by the time they were 59.
I realize it doesn't have the "release upon reaching $1 million" feature, but it would penalize them for withdrawing it early, and they would have to become productive citizens in the meantime. It's also a very simple thing to do, no complicated trusts or lawyers.
The financial advisor Ric Edelman came out with a "product" along the same lines he called the RIC-E Trust. The idea was you could put away $5,000 for a child, let's say when they were born, which could not be withdrawn until retirement. Hypothetically if that had a 10% return per year, that $5,000 would turn into well over $1 million by the time the child was 59. That particular trust is based on a variable annuity so I don't know that I'd recommend it due to high expenses, but in theory you could put away $5,000 yourself, and put the proceeds into the IRA as described above once the child reaches working age and has some earned income.