I've defined myself as a Buddhist for a good 15 years. Yet I consider myself to be an atheist as well. I see no contradiction in this as I don't consider Buddhism at its core to be a theistic religion; to my mind, mindful living is the goal, and god/desses are culturally-dependent and basically optional.
I wonder though if I put Buddhism on my various social networking profiles, as I have, if that turns off people who are strongly agnostic/atheist because they might lump me in with other theists. I don't even formally practice Buddhism, currently; for me it's more a mindset and lifestyle.
I also have described myself in various places as "semi-pagan" but I'm realizing that is less and less accurate. I identify with the idea of honoring the Earth and with having open relationships, but neither of these require a religious or ritual structure. I have participated in a few pagan rituals at poly events and while they don't bother me, I can't really identify with the content. Unlike Buddhism, I'm thinking I should probably drop any stated affiliation with paganism as it really doesn't capture who I am well.
Just some random thoughts as my energy flags this late afternoon...