Fax numbers from another thread:

Sen. Max Baucus 202-224-9412
Sen. Mark Begich 202-224-2354
Sen. Susan Collins 202-224-2693
Sen. Kent Conrad 202-224-7776
Sen. Byron L. Dorgan 202-224-1193
Sen. Judd Gregg 202-224-4952
Sen. Kay Hagan 202-224-1100
Sen. Kay B Hutchison 202-224-0776
Sen. Scott Brown 202-228-2646
Sen. Mary Landrieu 202-224-9735
Sen. George LeMieux 202-228-5171
Sen. John McCain 202-228-2862
Sen. Lisa Murkowski 202-224-5301
Sen. Bill Nelson 202-228-2183
Sen. Mark Pryor 202-228-0908
Sen. Olympia Snowe 202-224-1946
Sen. Jon Tester 202-224-8594
Sen. George Voinovich 202-228-1382

Feel free to add Senators and numbers to the list.