Thanks. I'm glad everyone is liking it.
Scott - There's plenty of watermark creation software available. I use a Mac and have an app called Watermark Pro. It's very simple to use.
If you have a PC, I'm sure there's something similar. I think eBay can insert a watermark onto your picture when you list. From eBay's
Photo Requirements page:
Watermark policy
Watermarks are allowed for ownership and attribution, but not for marketing information, specific details about your item, or customer service. Your watermark should be no bigger than 5% of the total image area, have an opacity of no more than 50%, and never obscure the item. Links are not allowed in watermarks.
To make sure your watermarks are compliant, use the eBay watermark creation service. You’ll find it in the “Bring your item to life with pictures” section of the listing form.