This plugin, when combined with Phil's Exiftool, will place EXIF data from your image directly onto your image as text layers.
It currently will place Shutter Speed, Aperture, ISO, and camera Make.
All I did in modifying it was to (in windows only) have each EXIF tag be placed on the image canvas as separate text layers for further modification (font, size, justification, etc...).
You'll need to download and install Exiftool by Phil Harvey. You'll also need to know the path to the exiftool.exe file (or exiftool binary in *nix).
Download this plugin, and place it into your GIMP plug-ins folder (in GIMP, Edit -> Preferences -> Folders -> Plug-Ins will tell you the location to place it). Rename the file to ExifInfo.py (remove the .txt).
Then EDIT THE FILE. You only need to paste in the path to exiftool at the appropriate location. (You'll find a line in the file that says ###FULL_PATH_TO_YOUR_EXIFTOOL_INSTALL### for windows. *nix users will find it where it has /usr/bin/exiftool (change it if you need to).
I haven't gotten around to modifying this for *nix users yet, but will as soon as I have some time on my other machines.
This is a modification of the original script ExifInfo.py by meetthegimp.org forum member WarEagle.
The original forum topic is here: