Ben Huff over at Times and Seasons has an outstanding post drawing parallels between the LDS temple ceremony and the Catholic Mass (while also noting the key differences) in order to help those outside the LDS Church understand what goes on in the temple:

In a Catholic Mass, a congregation sits facing a priest, in a symbolic space, with an altar at the front, and participates in a standardized ceremony in which their spiritual relationships with one another and with God are symbolically represented and (re)affirmed. The priest leads the ceremony, with others assisting at various points. There are things the priest says, and responses by the congregation. The congregation stands and sits at various points, as part of this response, corresponding to whether they are praying or listening or reciting a creed or what have you. The Gospel is taught, and actively received. At the climax of the ceremony, each member of the congregation goes forward for a symbolic reunion with God, in this case represented by the priest and the Eucharist, in which God is said to be present.

The same basic format applies to the Mormon endowment. A congregation sits facing an officiator, in a symbolic space, with an altar at the front, and participates in a standardized ceremony in which their spiritual relationships with one another and with God are symbolically represented and (re)affirmed. The officiator leads the ceremony, with others assisting at various points. There are things the officiator says, and responses by the congregation. The congregation stands and sits at various points, as part of these responses. God’s plan of salvation is taught, and the teaching is actively received. At the climax of the ceremony, each member of the congregation goes forward for a symbolic reunion with God, in this case represented by entry into the Celestial Room, representing the presence of God.

Be sure to read not just the whole post, but also the comments, which are not only thoughtful but contain some links to additional analysis.

[UPDATED 01/25/08 – 1512 MST] You might also want to read this article (“Knocking Three Times on the Holy Door“) over at the excellent Temple Study blog. ..bruce..