If you want to geotag your photographs, then you have to be prepared to either spend money doing it automatically, or spend time doing it manually.
If you have the time, you can edit the lat/lon pairs into the exif section of each pic, and it will be placed automatically when you upload to onlline albums like Flickr (not all have the facility though - check! ). You can also edit the album tags for the pics, and this will do the job too, but it's not much fun if you have hundreds or thousands of pics.
If you have the money, you can buy a digital camera with a GPS receiver built-in. Provided you can sniff enough satellites, it will geotag your pics at the moment you take them. The downside is that there are only a few cameras with this option built in, and they are priced correspondingly. There is also the small matter of not having much choice of camera, and if you decide you don't like it, you either stick with it, or lose the automatic geotagging when you ditch it.
There is now a third option, provided you are lucky enough to own a select few camera, or are about to buy one from the supported few.

An add on geotagger will inject the lat/lon pair into the exif data, ready for use by the online album service, or just for your own use to identify the location later.
The
Macsense Geomet'r GNC-35 GPS isn't that expensive or cheap, and the cameras it works with aren't amongst the least expensive or simplest dSLRs, Nikon D700, D300, D3, D200, D2Hs & D2Xs, and Fujifilm S5 pro cameras. however you can swap the unit between various models.
It's about £100 in our money, so if you have those cameras, it's a reasonably priced option if you have such cameras.
What's more important is the existence of the thing, and the fact that it can be produced as an accessory. That's no great surprise given the technology, and maybe means that more of these will appear, and for lesser cameras, which would be a boon.
Instead of having to remember where you were when the police cart you off for having a camera in public, all you'll have to do is try and take pic before the cuffs are slapped on
