How many denominations participate in Stephen Ministries?

From their website:

Stephen Ministries organization and developed the Stephen Series, which now has been implemented in more than 10,000 congregations representing more than 150 Christian denominations. More than 500,000 laypersons have been trained as Stephen Ministers, who in turn have ministered to more than a million care receivers.

Tens of thousands of pastors and lay leaders trained as Stephen Leaders to direct Stephen Ministry in those congregations. And hundreds of thousands of lay Stephen Ministers reaching out with Christ's love to hurting people. But biggest of all is the number of people whom God has cared for through a Stephen Minister. More than a million--and growing.

Has a staff of about 45 dedicated people--pastors and laity--from a variety of denominational backgrounds

As in being crucified upside down?

Not many.

Catholics do. Not sure about others