PICASA (now version 3.8)

Question : Do you know any good, free, and easy to use software that can help me to organize,editing and share my photos online?

Answer : Yes. Picasa.

More information and Download here http://picasa.google.com/

Some screenshot

and...the instant collage maker..here's the example

 collage

For me it's quite handy..even for professional..how about you?