Pictures I make with the camera, sure. Not the ones I sync'ed from a folder via iTunes. Closing the apps does absolutely nothing. I use mail, facebook, safari, engadget, beejiveIM and twitter and yet in the middle of a day the phone's UI becomes jerky and laggy and the same apps crash on opening or take ages to load / resume. Clicking on refresh of all mail inboxes and switching to engadget makes the phone cry in the afternoon. Running 4.3.3 btw.
In general I didn't like the way things are managed on the phone from the beginning. The more I use it, the more I hate it - everything is done in an inefficient way in my opinion and is very different from what I'm used to. Also, iTunes is an abomination. Hence, I don't like it and won't be buying anything Apple again, unless there's going to be a miracle with iOS5.