I once worked with a priest who liked one part of the Mass to flow seamlessly into the other. He would often roll smoothly from the opening dialogue into the penitential rite. Another preference was to begin the Creed while he was still in the ambo, right after the last sentence of his homily.
More frequent is the custom of praying the Liturgy of the Word in quick succession: reading-psalm-reading-alleluia-gospel. In my present parish, we frame the first three scriptures–including the psalm!–with twenty to thirty seconds of silence.
My armchair question of the day: What parts of the Mass lend themselves well or better to being prayed in quick succession without silence?