The Pledge of Allegiance was created in the late 19th century, but 'under God' was not added until 1954. The addition may have made sense at the time (to set Americans apart from the godless Communists), but is now an unnecessary piece of the pledge that only serves to drive a wedge between various factions in the country. The pledge conveys the same intent without the addition of God.
The fact is, the connotation of the words 'under God' are Judeo-Christian beliefs. Some people call their Diety by other names, and yet others do not believe in dieties at all. Placing 'under God' in more governmental representations is counter-productive to the true freedom of religion and the separation of church and state. It's time to evolve out of this oppressive mind-set.
America is more secularized than it every has been in the past. We are also trying to foster religious freedom and not all religions are directly attributed to God, as some people understand that entity. For that reason, I do not believe more American entities should ascribe to the phrase 'under God' as stated in the Pledge of Allegiance.
I think it's largely a personal choice whether or not you ascribe to that phrase, it's been hotly debated in recent years if this phrase is appropriate to be used in schools and overall I think in the end everyone has to make the choice if you are comfortable saying and ascribind to it or not.