A Totten Trust is somewhat of a misnomer because it is a trust in name only.
In reality, there is no trust document. Rather, it is an informal trust arrangement
accomplished by titling a bank account or other asset in the fashion of "Homer Simpson in trust for Marge Simpson." This means that during Homer's lifetime he has total control over the account and complete access to it. However, at his death, the property passes automatically and outside of probate to Marge.
The asset still may be subject to estate taxes if the estate is large enough, but it does not have to go through probate -- Marge would have immediate access to the account.
In certain specific instances, Totten Trusts can be a good alternative to having someone added to the account as a joint owner. However, the vagueness of the informal trust does not make this a very good choice, except in limited circumstances for small amounts of money.
In most cases, you would be better off by actually setting up a living trust. With a living trust, you can approve the trustee and beneficiary during your lifetime, as well as precisely provide for how you would want the property to pass at your death.