We used uMark Lite after finding an article on http://www.pcadvisor.co.uk/how-to/photo-video/3446977/how-watermark-images/
It was easy to use and was free!
Just remember to refresh the page after uploading the watermarked images.

I'm always a bit wary about downloading free software, especially after a recent episode of a download that obliterated my anti-virus! However I looked at this soft ware and it looked OK and has been recommended so I've given it a go.

It seems to work perfectly.

One small observation is the watermarked picture is happily a copy of the original. This keeps the original and the new picture goes into a new folder. Note that the file size of this copied picture is smaller than the original so if you wanted to perhaps pass this photo onto someone/somewhere were definition is crucial there may be a loss of picture quality.

I shall watermark all pictures now going into the public domain.

Finally thank you for flagging this program up

Davie  8)

We was sent this link today to get the latest version of uMark Professional for half price.  Just £10 with the current exchange rate.
We have used the link, but should be OK for anyone else to use.

http://www.uconomix.com/NewCart.aspx?c=HALF

I don't know of any good free software that enables you to add embedded, hidden watermarks. Expensive software like Photoshop can have plug-ins like Digimarc added to them. The advantage of using this is that it doesn't distract from the photo itself and is very useful in the event of photo theft.

However if you have the right software these can be removed, as can the obvious visible watermarks, but both are a good deterrent to simple photo theft.

TSR Watermark Image is good free watermarking software for personal use. You can easily customise your own watermark, place it where you like in the image, control the watermark opacity and much more with no nag pop-ups as far as I'm aware. The free version does most of what the paid version does, apart from restrict you to a single watermark. Watermarking photos can be that extra bit of security for those less confident about posting photos of themselves naked online.

I know concerns about free software have been mentioned; I use a large range of free and paid for software and consider this one 'clean'. I use a combination of obvious and hidden watermarking. I prefer to place the visual watermark near the margins as this does not take centre stage and distract so much. Of course this can be cropped out by a thief but the embedded watermarks are my back up if this happens. It might all seem like over the top behaviour but I use photos in professional situations so I do the same for all of my images wherever they're used.

http://watermark-image.com/download.aspx

The website has good, clear instructions on what it can do and how  to use it.

Disclaimer: I have no connections to this company.

Was sent another discount code for uMark.

Use the coupon code AUGDEAL and get 30% off on uMark.

http://www.uconomix.com/NewCart.aspx?c=AUGDEAL

We was sent this link today to get the latest version of uMark Professional for half price.  Just £10 with the current exchange rate.
We have used the link, but should be OK for anyone else to use.

http://www.uconomix.com/NewCart.aspx?c=HALF

Just a point about watermarks and copyright: copyright exists the moment someone creates something.  That little "c" in a circle is useful in showing that the creator wishes to control the reproduction of the material but, strictly, text and images are the copyright property of the owner (in the UK, at least) whether or not the symbol appears.  That being said, when you upload pictures to many sites there may be terms and conditions which you have implicitly agreed to which allow reproduction, circulation, etc.  Remember also that copyright is owned by the photographer not the model.  So if you model for someone else you may wish to have a clear written agreement as to what the photographs are for and who can see or use them. You, the model, could for example impose conditions on which publications, websites, etc. the pictures can be submitted to.  If the photographer is going to use the pictures to make profit there are additional legal issues if individuals are identifiable in the pictures - but there are lots of good sites run by photographic clubs and associations which can provide good advice.  Unfortunately, these days people seem to think that taking pictures of people in public places requires their permission - it doesn't providing you cannot be considered to be harassing them or being intrusive and providing you are not going to use their identifiable image for profit.  However, if the people in the picture are bigger than you, discretion might be in order!

We have received another discount code for uMark.  We use uMark for watermarking all the photos we upload to this site & BN and it is very easy to use.

"Get uMark at 40% off till the end of the month.

Use coupon code "OCTOBEREND" and get 40% discount on uMark."

This deal is available only till October 31.

http://www.uconomix.com/Products/uMark/Default.aspx

A 50% discount on uMark is available at the moment. See http://www.uconomix.com/NewCart.aspx?c=NOVHALF to get it at half price.

Given up trying to stop people copying photos to facebook....(my wife's a photographer) so now she just puts her name and phone number as the watermark.  At least if they get copied we get a free ad!