Each week at Mass, an assigned family is called by the priest to come forward to receive the chalice and a blessing. (This consecrated chalice is wrapped in a special cloth and along with a laminated prayer card is placed in a plastic chest). The family takes the chalice home and puts it in a place of honor. 

Each day for a week, during prayer time (morning, bedtime or at meals), the family prays for an increase and perseverance of vocations. They can also send a note of support to a Seminarian, Priest or Sister. The following weekend, the family returns the chalice box for another family to take home. 
 

The purpose of the Chalice Program is to encourage families to pray and promote vocations to the Priesthood, Religious Life, strong Catholic marriages and holy single life. The consecrated Chalice is a tangible reminder of this special intention for the Church. The Second Vatican Council highlights the responsibility of the laity to pray for and support vocations. This urgent call has been strongly affirmed in the writings and addresses of both Pope John Paul II and Pope Benedict XVI. 

Praying for vocations is the most powerful way to support vocations. A vocation is a call from the Holy Spirit, a gift from God that is nurtured in prayer. When we pray for vocations, we lift up to our Father those men and women whom He is calling to follow Him in a very special way. We hope that those who bring the cup home will continue to pray daily for vocations. 
(from USCCB website)