I strongly urge you not to donate to them this Christmas. There are clearly better charities to give your money too. I have also stumbled onto an interesting to campaign that give you a way to tell the Salvation Army that you are making this choice.
Give money to a GLBT friendly charity, print out a few of these, and put them in those Salvation Army kettles when you see them this Christmas. Maybe the Salvation Army will finally see that hatred of the GLBTQ community is no longer acceptable in our world.