Here is how you can remove your Demo, Personal Use even Gifts and more from your Inventory:
Click on your Sales tab and Create an invoice like normal using yourself as the contact
Once the invoice is created you can now enter in the products and under the column Sale Type you can choose the option that best fits your situation
When finished be sure to click on Save and then mark your invoice as delivered
Here are instructions for marking your invoice delivered : http://support.pinkoffice.com/article/151-how-do-i-add-a-payment-to-an-invoice-and-show-that-it-has-been-delivered
Once you have Saved and Marked your invoice as Delivered your products will be removed from inventory and Tracked in your Tax Info Report!