My pictures look dull and desaturated in other monitors

[iluvphotography]

I use an iMac at home for processing my photos.&nbsp; When I upload them to different sites and look at them in other monitors or even on my iPhone, the colors are not as vivid and vibrant as I see in my iMac.&nbsp; They are desaturated and blah....<BR>What should I do?<BR>