There are plenty of ways to transfer photos from an iOS device to a Mac--I generally email them to myself or use Messages--but it can still be a hassle. A tip recently published on The Iconmaster could be my new solution to the problem.
First, make sure you have Photo Stream turned on in each of your iOS devices, as well as on your Mac. Next, go to your ~/Library/Application Support/iLifeAssetManagement/assets/sub folder. There, you'll see a bunch of subfolders with names like 013184d3f181aa175db7e48b08817861eff8cac25a. (If you aren't sure how to get to the Library folder inside your home folder, here are 18 ways to do so.) Perform a search for image files in this sub folder by typing kind:image in the search field and selecting Sub as the focus of the search. (If you take a lot of photos or screenshots, and only want to find one or the other, you could instead search for png for screenshots or jpg for photos.)
Now save this search as a Smart Folder by clicking on the Save button just below the search field. You can save it wherever you want: by default, it will go in the Saved Searches folder, but you can check the box that says Add to Sidebar if you want quick access from the Finder sidebar. You can also choose a different location for the Smart Folder, such as your Desktop. If you want this folder in the Dock, add it to the Dock by dragging the folder there.
That done, whenever you need to get quick access to a photo or screenshot that you took on an iOS device, just open this folder and find it. If you have a lot of files, you might want to add the Date Created column (right-click on the sort headers and choose Date Created from the list), then sort by this date (click on that header so the most recent date is at the top).