WordNet (r) 3.0 (2006):

pep talk
    n 1: a speech of exhortation attempting to instill enthusiasm
         and determination in a team or staff

Moby Thesaurus II by Grady Ward, 1.0:

63 Moby Thesaurus words for "pep talk":
   address, after-dinner speech, agitation, allocution, arousal,
   chalk talk, debate, declamation, diatribe, eulogy, exasperation,
   excitation, excitement, exhortation, filibuster, firing,
   fomentation, forensic, forensic address, formal speech,
   funeral oration, harangue, hortatory address, inaugural,
   inaugural address, incitation, incitement, inflammation,
   instigation, invective, irritation, jeremiad, oration, pep rally,
   peroration, philippic, pitch, prepared speech, prepared text,
   provocation, public speech, rabble-rousing, reading, recital,
   recitation, sales talk, salutatory, salutatory address, say,
   screed, set speech, speech, speechification, speeching,
   stimulation, stirring, stirring-up, talk, talkathon, tirade,
   valediction, valedictory, valedictory address