I just purchased a D90 this passed week with the intention of buying a aftermarket GPS. I have read a lot about the jack on the D90 breaking from wiggling plugs. Is there a GPS that works well and has a decent plug?
I own three different GPS' for my Nikon bodies. The one that I like the best a GeoTagger N2. It has a detachable cord that you can switch to match different bodies. For anyone who travels I can recommend a GPS on your camera very much. You would be suprised as the years go by how you forget exactly where a picture was taken. Now with Google earth and the embedded data in the photo, you can click on it and see within a couple feet where you were standing. Way Cool !!!
Another alternative, which works very well but depends on having a smartphone, is using an app called Geotag Photos Pro, only £2.49 on the app store. Not sure if there is an android version.
With this app, you ensure your camera and smartphone are set to the same time. You then use the app, when taking photos, to create a log which can be synced with the data on the phone, with for example Lightroom 4.
Of course, if you don't have a smart phone, this has been a useless piece of advice!