GPS for Pentax K5, Kr, 645D

I find it interesting that this device can control the sensor position while plugged in via the hotshoe. That suggests there is an API... we just need to discover it

Eye-Fi have SDHC cards that Geotag from Wi-Fi Hotspots.

http://www.eye.fi/how-it-works/features/geotagging

Sadly only in the city you might find wifi hotspots though

If you've got Apple Gear they have already recorded where you've been

Ask them nicely to Geotag your photos If they haven't already

http://www.wired.com/gadgetlab/2011/04/iphone-tracks/

Another article on the Pentax unit: link

If you have an Android phone, the same is also true Algi, link from the same site.

With all the excitement surrounding this GPS unit I actually decided to get off my backside to workout what I could do with the kit I already have and found out that I have been rather stupidly lazy and just saved myself £200!

The kind of photos I want to geotag are all the nature shoots I'm currently doing and with the kit I have, that normally means staying put in one spot. Simple answer? Take a photo with my iPhone as this does indeed automatically Geotag the photo. Getting this information into my photos is also A LOT easier than I thought as Aperture will just grab the location from the iPhone photo as seen here.

Location data also gets transferred to the iPhone when syncing albums to it which makes it easier to share locations when I meet up with fellow shooters and exchange tips etc.

Cannot believe just how stupidly lazy I have been in not sorting this out before! Now off to tag all my photos!

To be frank, the Pentax GPS unit does a bit more then just geotag but if that's all you need then indeed there are far cheaper options avaiable also.
Many smartphones have GPS that can do the same thing and there are cheap GPS loggers avaible as well.

There are even watches that record your movement with GPS...
http://www.suunto.com/en-US/Products/Outdoor/suunto-X10/Suunto-X10/

Looked into that a while ago Stefan, especially when Apple opened up the iPhones multitasking to all developers, but most reviews were showing that the battery was getting drained really fast with the loggers, some as little as 4 hours and there was no way I was going to do that.

The 'take an iphone photo - add GPS from iPhone option in Aperture 3' is just so damn easy that I'm kicking my self for not having looked into it before. The only option missing that I would like would be which direction I was facing in. Will now have to look and see if the compass data is added to iPhone photos.

If so that still wouldn't be very usefull for your photos taken with the other camera unless you're planning to take a photo with your DSLR and then with your phone every time but that gets really time consuming I think.

Not a problem for what I need.

Just the one iphone photo needed per location and it's normally one location a day.

You really need one of these:

http://www.pentaxsurveying.com/en/midden-smt888-appl.htm