Anyone you can count on to handle money wisely could be your trustee. You will want to choose someone who will act according to your wishes and make good decisions about the details of your Trust. This person may be a friend or family member and in some cases could also be one of your beneficiaries. However, the trustee should be a US citizen or a lawful permanent resident (aka green card holder). If a non-US Person (defined in the tax code) acts as trustee, some very nasty tax consequences can result.
Our blog post describes the responsibilities of the position and what is involved.