*(such as by clicking Photo Stream under Media in the standard File..Open dialog box in recent versions of Mac OS) *Note: Photo Stream only syncs the last 30 days of your photos.
Also, I've found that only photos taken after [Photo Stream is set to On] will be transferred.
Eg photo A exists on my phone, and the setting Photo Stream is off.
Update: Murphy's law though the actual photos I really care about seem stuck in Photostream purgatory and won't appear on other devices.
Perhaps this is why Steve Jobs was rumored to have offered Dropbox so much money to sell? I had taken 40 or so photos on i Phone 4, i OS 5.1, and when I got back to Wi Fi connection, I waited more than an hour for the photos to appear in Photo Stream either on the i Phone or my i Pad, and they didn't.
Within one second my phone started uploading the new image, and within 10 seconds it was live within my Photo Stream. You needed to earn 10 rep here to answer a protected question.
If you're having long delays check your Wi Fi connection - This may not be the only reason for a delay, but it helped me in my situation. I think I fixed that with my vote up of this excellent answer.One possible explanation could be that Apple is currently working on their Photo Stream data base?(after the spinning icon goes away) open i Photo on my Mac, the photo appears in my photo stream.When you turn on Photos, i Cloud for Windows creates a Photos folder in File Explorer called i Cloud Photos.My Photo Stream automatically downloads any new photos that you take on your i OS devices to the Downloads folder.None of the following worked: Eventually, after an hour or so, in desparation I forced the i Phone to power-down, and turned it back on.