PowerBlog! has a great suggestion:
I’m sick of seeing anything remotly connected to Christmas being forced from the American landsacpe. The ACLU is behind most, if not all of it. So I thought we should all get together and send a Christmas card to the folks over at the ACLU.
I once sent a Meat Lover’s pizza to the folks at PETA. Never even got a thank you but it’s the thought that counts. If you care to send a bit of Christmas cheer to the lost people at the ACLU here s the address:
ACLU of PA
Greater Pittsburgh Chapter
313 Atwood St.
Pittsburgh, PA 15213
BTW, I’ve decide to back off from my suggestion of not using "Merry Christmas" (hence the title). I still think something like the Easter exchange of "He is risen" and "He is risen indeed" would be cool. Perhaps "He is with us" and "He is with us indeed" (because Immanuel means "God with us") would work.