PhotoStream tip
PhotoStream is neat but you can't delete phots from it so ALL the photos, even the mistakes, etc. go to PhotoStream... unless you turn on Airplane mode first. This works if you want to delete bad photos before they get synced to Photostream. Before taking pics - turn on Airplane mode - this will stop wifi, etc. Now take as many pics as you want then go through the camera roll and delete the bad ones, mistakes, etc. so you just have the pics you want. Then turn Airplane mode off and PhotoStream will just upload the photos you've chosen.
Obviously, this won't work for pics taken in a hurry but when taking a bunch of pics on vacation, it'd be easy to do this - worked for me so far.
imac, macbook, ipod nano & iphone & iPad!, Mac OS X (10.6.3)