I did edible fruit arrangements for my evaluators. I don't think it is bribery, considering that their eLors are already in. I might have a slightly unusual situation though; my evaluators are across 3 states and I haven't seen one in 7 years, the other in since Hurricane Rita, and the third I work for now. I sent a thank you card expressing my gratitude for the time, energy, and effort they put into completing the eLor with the arrangement, along with some more recent photos of some of my adventures (search/rescue, SCUBA, marine mammal stranding network.) In turn I have received pics of kids and spouses, updates on research and programs, and information on old friends.
Oh, and my boss shared her arrangement for the entire office (I think the Saturday morning coffee & bagels would be more of a bribe!) When I was in school and profs were giving me references, I did thank you notes and cookies or candies.