In honor of the Year of the Eucharist, Pope John Paul II has approved a special plenary indulgence for certain acts of worship and veneration of the Most Holy Sacrament (text from Catholic Online):
"According to a decree of the Apostolic Penitentiary, during the Year of the Eucharist a plenary indulgence may be gained by participating in acts of worship and veneration of the Most Holy Sacrament, as well as by praying vespers and compline of the Divine Office before the tabernacle."The objective of the papal disposition, the document indicates, is to "exhort the faithful in the course of this year, to a more profound knowledge and more intense love of the ineffable 'mystery of faith,' so that they will reap ever more abundant spiritual fruits."
The decree reminds the faithful that to obtain a plenary indulgence it is necessary to observe the "usual conditions": "sacramental confession, Eucharistic communion, and prayer in keeping with the intentions of the Supreme Pontiff, with the soul completely removed from attachment to any form of sin."
In the Year of the Eucharist -- which began October 2004 and will end October 2005, when the world Synod of Bishops will be held on the Eucharist -- the plenary indulgence may be obtained in two ways.
In the first place, according to the decree, "each time the faithful participate attentively and piously in a sacred function or a devotional exercise undertaken in honor of the Blessed Sacrament, solemnly exposed or conserved in the tabernacle."
In the second place, it is granted "to the clergy, to members of institutes of consecrated life and societies of apostolic life, and to other faithful who are by law obliged to recite the Liturgy of the Hours, as well as to those who customarily recite the Divine Office out of pure devotion, each and every time they recite -- at the end of the day, in company or private -- vespers and night prayers before the Lord present in the tabernacle."
The decree also provides the granting of the plenary indulgence to those persons who, due to illness or other just cause, cannot participate in an act of worship of the sacrament of the Eucharist in a church or oratory.
These persons will obtain the plenary indulgence "if they make the visit spiritually and with the heart's desire, with a spirit of faith in the real presence of Jesus Christ in the Sacrament of the Altar, and pray the Our Father and Creed, adding a pious invocation to Jesus in the Sacrament (for example, "May the Most Holy Sacrament be blessed and praised forever").
Since many people, Catholic or not, may not know what exactly is meant by an 'indulgence', I direct you to a very good explanation on Catholic.com (Catholic Answers Online):
"What is an indulgence? The Church explains, "An indulgence is a remission before God of the temporal punishment due to sins whose guilt has already been forgiven, which the faithful Christian who is duly disposed gains under certain defined conditions through the Church’s help when, as a minister of redemption, she dispenses and applies with authority the treasury of the satisfactions won by Christ and the saints" (Indulgentarium Doctrina 1). To see the biblical foundations for indulgences, see the Catholic Answers tract A Primer on Indulgences.
To see some common misconceptions and clarifications about Indulgences, click here.
UPDATE: What a Mystery has posted on this topic as well!