If you download Picasa to your PC it provides a wealth of useful tools for photo manipulation and displays all photos, (and videos) on your computer in a very easy to access way. If you wish you can hide folders. From Picasa you can send a photo to the external site called 'Creative Kit' where you can resize photos. All this is free.
I'm sure there are other photo manipulation softwares out there; I'm very happy with Picasa.
You can download Picasa here:
http://download.cnet.com/Picasa/3000-2193_4-10160334.html
