Yeah congratulations, you can quote the Bible. But do you know what it means? Do you know why these particular words were chosen? Do you even know who wrote them?
I'll say up front that I haven't studied the Law yet, so don't expect any deep theology on the meaning of "God's Jealousy" right now. However, I would like to raise the point that the Tanakh is the oldest part of Hebrew Scripture, before all the prophets. Thus, if you accept the understanding that our view of God grows and deepens over time, you must realise that the first books portray God according to the simplest, most "primitive" (meaning first, not "uncultured") way. They saw and understood God as a child would, in human terms. "Since God doesn't like people worshipping things that aren't him, he must be jealous".
Jealousy as known to humans (ie envy of what others have) is selfish and sinful. However, God is by definition incapable of either selfishness or sin, thus it is impossible for him to be "jealous" as humans know it. Rather, his "jealousy" is a poor way of describing his reaction to sin. I mentioned before that all sin springs from selfishness - wanting for ourselves that which we should really want for God (namely, authority, power, control, glory, praise etc). In our selfishness we turn away from God and make ourselves our own "gods", acting for our own glory instead of for His. In doing so, we deprive ourselves of His divine presence (since we cannot serve both God and ourselves, thus casting Him out of our lives) leaving us incomplete. Ultimately, we grow to hate God as a competing force, and since those who are hateful to God can not stand be in his presence, they must go to a different place, a place totally without God. For those playing at home, this is the definition of hell. Basically, in his total respect for free will, God gives people hell because they could not stand to be in heaven - hell is a choice of the individual, not of God.
Having written all that, I finally had a chance to go back up and read Wilmo's point properly and realise that it wasn't him who was wrong but the interpretations of those who read his post.