Many people choose to launch iPhoto or Aperture when connecting the iPhones to Macs for the ritualistic "sync" operation -- but if you don't actually do it, or worse, disable the launch of a photo app you can leave your iPhone's photos in great peril.
The problem is that iPhone photos aren't automatically backed up, and if you trash your iPhone by installing one too many JB apps -- or otherwise need to restore it -- your precious photos could be deleted. On the last couple editions of the PowerPage podcast both Rob and I have lament losing iPhone photos in a hasty restore and a couple of good tricks for recovering data from restored iPhones were mentioned.
As an alternative you can always use Image Capture to re-enable the automatic launching of iPhoto or Aperture -- but you'll still have to remember to import your photos there too. None of these is quite as seamless as something built into iTunes though and Apple needs to add automatic photo syncing to iTunes, soon.