WordNet (r) 3.0 (2006):

sweet nothings
    n 1: inconsequential expressions of affection; "he whispered
         sweet nothings into her ear" [syn: sweet nothings,
         honeyed words]

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "sweet nothings":
   adulation, artful endearments, blandishment, blandishments,
   blarney, bunkum, cajolement, cajolery, caress, compliment,
   endearment, eyewash, fair words, fawning, flattery, grease,
   honeyed phrases, honeyed words, incense, oil, palaver, pat, praise,
   pretty lies, soap, soft soap, soft words, sweet talk, sweet words,
   sycophancy, wheedling