Start by entering the new item number and then press the copy button at the top of the form. A new form will pop up asking you to select which item you wan to copy from and allow you to choose whether or not to copy things like the price list, site assignments, vendor and currency assignments.
Once you click copy, you get a new item that let's you make whatever changes you want. You'll probably want to adjust the description at a minimum but much of the tedium (Price Lists, List Price, Site Assigments) is already done for you.
Now, go enjoy that weekend.