WordNet (r) 3.0 (2006):

bend over backwards
    v 1: try very hard to please someone; "She falls over backwards
         when she sees her mother-in-law" [syn: fall over
         backwards, bend over backwards]

Moby Thesaurus II by Grady Ward, 1.0:

21 Moby Thesaurus words for "bend over backwards":
   be careful, be cautious, be fair, be just, do justice to,
   exercise care, give and take, handle with gloves, have a care,
   lean over backwards, redress a wrong, remedy an injustice,
   see justice done, shoot straight with, take care, take good care,
   take heed, take pains, take trouble, tread on eggs, treat gently