James Grant has a post in which he considers the opinions of certain Christian leaders with regard to Christians observing Ramadan as an outreach to Muslims. You can read it here. There is absolutely no way that we should make a concession with regard to such a religious practice to a false god. Our definition of love, as well as our methodology of evangelism, are to be gleaned from Scripture, not from what some emergent churches practice. I have heard several individuals speak of respecting these practices in their communities.
I appeal to you, brothers, to watch out for those who cause divisions and create obstacles contrary to the doctrine that you have been taught; avoid them. For such persons do not serve our Lord Christ, but their own appetites, and by smooth talk and flattery they deceive the hearts of the naïve. (Romans 16:17-18)