Thanks for the enlightenment about the Jewish mystics. That, I suppose, is why we occasionally see G_d in these discussions.
Judaism does not prohibit writing the Name of God per se; it prohibits only erasing or defacing a Name of God. However, observant Jews avoid writing any Name of God casually because of the risk that the written Name might later be defaced, obliterated or destroyed accidentally or by one who does not know better.
The commandment not to erase or deface the name of God comes from Deut. 12:3. In that passage, the people are commanded that when they take over the promised land, they should destroy all things related to the idolatrous religions of that region, and should utterly destroy the names of the local deities. Immediately afterwards, we are commanded not to do the same to our God. From this, the rabbis inferred that we are commanded not to destroy any holy thing, and not to erase or deface a Name of God.
It is worth noting that this prohibition against erasing or defacing Names of God applies only to Names that are written in some kind of permanent form, and recent rabbinical decisions have held that writing on a computer is not a permanent form, thus it is not a violation to type God's Name into a computer and then backspace over it or cut and paste it, or copy and delete files with God's Name in them. However, once you print the document out, it becomes a permanent form. That is why observant Jews avoid writing a Name of God on web sites like this one or in BBS messages: because there is a risk that someone else will print it out and deface it.
Normally, we avoid writing the Name by substituting letters or syllables, for example, writing "G-d" instead of "God." In addition, the number 15, which would ordinarily be written in Hebrew as Yod-Heh (10-5), is normally written as Tet-Vav (9-6), because Yod-Heh is a Name. See Hebrew Alphabet for more information about using letters as numerals.
Abominable behavior quickly followed, e.g. abortion and mainstreaming of homosexuality. Those are symptoms of the disease, i.e. "officially" blinding this nation to God.
He that sitteth in the heavens shall laugh: the Lord shall have them in derision. Then shall he speak unto them in his wrath, and vex them in his sore displeasure. - Psalms 2:1-5