I would use an iPhone or iPad, then no plugins would be needed.
What we have working here is to take normal digital cameras and replace the standard SD chips with EyeFi cards. We've then set the EyeFi cards and software to automatically download into a shared folder on our network. (EyeFi SD cards use the local WiFi to download images to a folder in a computer on your local network.)
This is set up for a fileMaker 10 system so I didn't have all the bells and whistles possible in 12 to work with, but What I came up with was a combination of batch file command lines and Import Records | Folder to import all the images found in that folder into a table as embedded and then delete the files in the folder so as not to import the same files the next time.
The images are then exported to a different shared directory and re-inserted as "by reference" pictures. A simple point and click interface with buttons and scripts allows the user to look at the images in a portal and click one to select it for the current record.
I will try both these methods