While many criticize Xmas as a way of removing Christ from a holiday honoring Him, the “X” actually stands for Christ. Read about this here.
I did know about this already, but I agree with Doug – it’s better to spell out Christmas for the people who are unaware of its significance. I think doing this is similar to, but not the same as, 1 Corinthians 8:13.
(Link via blogs4God.)