I have a picture in digital format, on which I would like to put some comments in my handwriting.
The only way I know is to print the picture, add the handwriting and to scan it again. But this will require a very high quality printer.
I am looking for some method, which will allow adding the comments without printing the picture.
Please advise
thanks

What, if any, "photoshop" type software do you have?

XP or Vista contains MS Paint which allows such editing with the "free style" pen.

Your handwriting will depend on your skill with the pen or you can use block text.

If you want to go more advanced you can get GIMP for free:

GIMP - The GNU Image Manipulation Program

Hi idr...

Just to add to jephree's comments. Does the "handwriting" have to be your handwriting? There are many handwriting fonts. I use a free "Image Editing" program called Paint.Net...I used it on a pic and added it to this thread as an example. You can get Paint.Net from...
Paint.NET - Free Software for Digital Photo Editing