You could draw your signature with a felt tip pen and either photograph it or scan it into your computer, this will give you a very personal to you signature, better than just using the type tool.
Open it in PS and you can select just the black lettering and turn it into a brush, you can build an Action around it to put it into the same place on any picture automatically, you can re-size in the same action if you want.
The best way of protecting images on the net is only to upload very small files, these will never print with any quality.
You can also edit an IPTC metadata file to include all your copyright detail and save it, then Bridge can automatically insert it into the EXIF data when you download them onto your computer.
In Bridge go to Tools>Create Metadata Template, fill in all the fields you want included and save the file.
When you come to download new pictures use the Bridge>File>Get Photos from Camera and in the dialogue box that opens at the bottom of the right hand panel there is a drop down menu the file you just created will be there, select it and the IPTC data will be included in the EXIF date attatched to all the pictures. It's not a 100% solution as the data can be edited, but most people don't know its there and only your data will be on the file on the website they downloaded it from.
Chris