There is a myth on the internet that any photo out there can be taken and used without payment and/or attribution. Make sure you are not a victim of this myth by protecting your work with My Watermark. See all Software reviews.
Some people seem to think that if they find an image they like on Google Images, then they can just take it and use it how they please. If you are the owner of that photo, being exploited like that both cheapens your work and possibly loses you licensing fees. So the solution is to watermark the image, to make it obvious that the image is yours. My Watermark is a portable application that helps you do this quickly and easily. See all software downloads.
My Watermark is a small portable application which you can place inside your Dropbox folder or on a USB stick. When you start it up, its first drawback becomes immediately evident - the app is donationware, which in this case means it's free to use, but for as long as you don't donate a minimum of $10, you are going to see a nag screen every time you start the app up, and every photo you watermark with this app for will have the developer's website URL on it.
If you find this app useful, and you think you are going to use it often, then just donate the $10. It will entitle you to use all of the developer's other software on his site too. So it may end up becoming a good deal for you. If you refuse on principle to pay money for software, you will have to learn to live with the website URL on your photos--or find another similar program such as TSR Watermark.
When loading photos into My Watermark, you have to load the folder where the picture or pictures are located. The app will then begin to generate thumbnails for each picture. The app claims this will speed things up, but I found that, while generating those thumbnails, the app was extremely slow and unresponsive, therefore frustrating to use. So if you have a lot of images in the target directory, it may be better to go off and make a cup of coffee while they all load.
Once they have loaded, you will then see that you have various options open to you. First, you need to type the text that you want as your watermark (such as your name). Then, you can specify the position of the watermark, the font, the color, and most importantly, the transparency. I have found that it is much better to have a softer looking watermark with a bigger transparency, so the picture itself is not ruined. But everyone will have their own tastes and the program allow you tweak these to your liking.
When you are ready to copy the finished watermarked image to your computer, just decide if you want them all placed in the same folder with a slightly different filename or in a separate sub-folder. Then click "watermark selected image". Or if you want to batch-watermark the entire folder, click "watermark all images in folder."
As you can see above, the watermark is really good quality, although you can't use images instead of text. The process is so painless that if you don't like the watermark, you can just go back in and redo it in a couple of minutes.