If you have a Mac with iPhoto or Aperture running, you can browse and geotag all your photos and on your iPad!
This is very convenient, because using a map with your fingers to set or view geotags is very intuitive on the iPad.
Browsing photos on the iPad is very nice, too. You can view photos fullscreen, and swipe to the next photo with your fingers.
PinApp needs an application on the Mac running, which enables the communication between iPhoto and PinApp. This PinAppServer can be downloaded for free from my website: PinAppServer.zip.
PinApp fully supports iPhoto '11 and iPhoto '09 on Mac OS X 10.5.8. or later.
Aperture is supported with V 3.5 on Mac OS X 10.9 (Mavericks) or 10.6.8 (Snow Leopard).
This screencast shows the interplay of PinApp with Aperture: