The biblical ritual of redeeming a firstborn male donkey with a sheep was performed by Orthodox Jews in Melbourne Australia on Sunday 3rd May 2009.
They called it the Special Mitzvah of Pidyon Petter Chamor. The story of the events leading up to this ceremony, including dramatic DNA tests, can be found at the Yeshiva World News.
Hat tip to our chavrusa Billy, a former Melbourne resident, for bringing all of this to our attention.
The relevant verses are:
Exodus 13:13 - But every first offspring of a donkey you shall redeem with a lamb, but if you do not redeem it, then you shall break its neck; and every firstborn of man among your sons you shall redeem.
Exodus 34:20 - You shall redeem with a lamb the first offspring from a donkey; and if you do not redeem it, then you shall break its neck. You shall redeem all the firstborn of your sons. None shall appear before Me empty-handed.
And the video speaks for itself...