How to get pictures from Mac to iPhone?

I have pictures that I transferred from a flash drive to iPhoto and now I need to put them on my iPhone. Is there a way to do this with my USB cord just by plugging my phone into the mac?

Well you probably have itunes installed you can do it through iTunes… Personally I would try dropbox and use the sync between the Mac and iphone to transfer files its the best way to transfer files esp if you have Wi-Fi connections available.