Thanks, for the suggestion !
But I've just discovered a great utility that does it all : PicaView from ACDSystems (part of the mPower tools). It's great! It just requires me to right-click on a file I want to see, and the program is embedded in the menu that normally appears when I right-click. It shows pics, video and plays mp3!

It not freeware, I've downloaded the 30 day trial version. But I already like it so much I'll most likely register it!

Thanks for all your help!