So I assumed there is no way to delete the pic from the iPhone, correct? If that's the case,what about if a person's away from his computer and he/she needs to delete some photos so that he/she can claim some memory back to use e.g. during vacation?
You can delete pictures on your camera roll on the iPhone. The other picture albums need to be deleted or removed using a computer that syncs with the iPhone, however.
I suppose if you are that low on space, you can delete apps and just sync them back when you get home however. Or you can email the photos on your camera roll to yourself and delete them.
So basically there is no answer to this question except workarounds. In my opinion, I think this is another bad design of the iPhone. I already love all the things that my iPhone can do but it just small things like this that I think Apple could have done it better. Why can't I delete the photos on my iPhone without tied down to a computer and if when I am syncing back to my computer it gives me the option if I want to sync from my iPhone to my computer or from my computer to my iPhone. I don't think that is so hard to do.
Note that all iTunes-managed media content is handled the same way - you cannot delete a song you don't want, either, without syncing to your computer. You may not like it, but at least it's consistent. Also, telling us doesn't help...tell Apple.