Hmmm... Microsoft Office Picture Manager ain't a patch on the old Microsoft Photo Editor that it 'replaced'... I still keep it on an old PC because it does a lot of jobs (resize, rotate, gamma, brightness, contrast, sharpen, soften, smudge, the list goes on) quickly and simply... I think Office 2000 was its last incarnation.

Picasa does a lot of those things, except PhotoEd could reduce brightness, contrast and gamma as well as increase... very handy.