Watermark a picture using Picasa

Open Picasa, click on a picture, to select multiple pictures, hold down the CTR key and click on another picture, any picture for that matter.

Now at the top left corner of your program, click on "File", select "Export Picture to Folder", check the option "Add a watermark:", type your message in the box, the text you enter here will appear on your image(s).

That's it, make sure you remember where you are saving your photos. Go ahead, upload them in Facebook or Twitpic. You do not need special software to watermark your photos.