In the movies, Pippin takes the Palantir and 'talks' to Sauron. Afterwards, he seems to have died, or at least gone unconscious. Gandalf then said some words, probably casting a spell. Was it some sort of a resurrection spell?
In the books, Gandalf doesn't say anything to revive Pippin; if he does perform magic, it's of a silent, non-verbal variety. To bring Pippin back to full awareness after he hypnotically delivers the message from Sauron, all he says is "Come back!" I interpreted this as just a natural thing for anyone to say to a person in a trance, but it's possible it was some kind of spell. Here's the relevant passage (emphasis mine):
He knelt by Pippin's body: the hobbit was lying on his back, rigid, with unseeing eyes staring up at the sky. "The devilry! What mischief has he done - to himself, and to all of us?" The wizard's face was drawn and haggard.
He took Pippin's hand and bent over his face, listening for his breath; then he laid his hands on his brow. The hobbit shuddered. His eyes closed. He cried out; and sat up, staring in bewilderment at all the faces round him, pale in the moonlight.
"It is not for you, Saruman!" he cried in a shrill and toneless voice, shrinking away from Gandalf. "I will send for it at once. Do you understand? Say just that!" Then he struggled to get up and escape, but Gandalf held him gently and firmly.
"Peregrin Took!" he said. "Come back!"
The hobbit relaxed and fell back, clinging to the wizard's hand. "Gandalf!" he cried. "Gandalf! Forgive me!"
-- The Two Towers, chapter 11: The Palantir
This fits with the form of the majority of Gandalf's magic. His will, expressed in ordinary words, is magic more powerful than that of Saruman or the Enemy. He puts forth all his strength to help Bilbo leave the ring behind, and uses similar methods to heal Theoden and Pippin.
Gandalf's other main expression of magic is simply his presence, as when he uncloaks himself in wrath at the Battle of Helm's Deep.
Gandalf's power is much more in who he is than in any magical spell.