This being me nick, I get asked this alot. Here's some I've discovered since:

    Astronomical Unit - A unit of length used in measuring astronomical distances within the solar system equal to the mean distance from Earth to the Sun, approximately 150 million kilometers (93 million miles).

    Angstrom Unit - a metric unit of length equal to one ten billionth of a meter (or 0.0001 micron); used to specify wavelengths of electromagnetic radiation

    Associate in Underwriting (insurance)

    Atomic Unit

    The Periodic Symbol for Gold (Au) - From the Latin word aurum.

    Arithmetic Unit

    Auxiliary Unit

    Alignment Unit

    Analyzer Unit

    Arbitrary Unit

    Arellano University

    American University

    Anderson University

    Aurora University

    Auburn University

    Angeles University

    Andrews University

    Anadolu University

    Amman University

    Air University

    Adelaide University (University of Adelaide, Australia)

    Absorbance Unit

    Access Unit

    Autistic/Autism

    Author

    Australia

    Australia's .au top level domain

    The music format with the file extension .au

    "Hey you"

    "Ah woo"

    "Ow"

    Somebody's Intials


For me personally, it's not an acronym or initials. It's simply two capitol letters and pronounced as if it were.