Recently I designed some wireframes for a site I am building. The wireframes were designed using Adobe Illustrator. Using the Artboard Tool I was able to layout all the pages I needed to build. The wireframes consisted of 12 pages. After the wireframes were complete I realized that I needed to add another page between page 3 and 4. Currently if you add a new page using the Artboard Tool it will only add a new page at the end,  so I ended up with a page 13. After browsing a few forums I ended up at the Adobe Illustrator Google Groups forum. There Jean-Claude Tremblay explained this solution:

Here is the solution:

1. Use the Rectangle tool to draw rectangle that cover the artboard size of all of your artboard except the one that you want to be the first. Using smart guide it will snap to the artboard. It’s IMPORTANT to draw them in the order you want your artboard to be re-order.
2. Now using the Artboard tool, delete all artboard except the one you did not draw a rectangle over.
3. Select all the rectangles from step 1. and choose Object > Convert to Artboards

Works like a charm. Try it out for yourself it is a great time-saver.