The iPod Touch has recently gained a location ability, despite not having a GPS. How?
A company, called Skyhook Wireless have driven around the US and Europe with a laptop and a GPS; recording the position and strength of every wireless access points SSID they detect.
A device, such as the iPod Touch, can have a database - or use the Internet - to go the other way: "I can see these APs with these signal strengths. Where am I?". A colleague tried this in the centre of London and it was accurate to within 20m!
The advantage of this on Maemo are obvious: for the N800, it provides a mechanism for knowing where you are (in built-up areas) without an external GPS. On the N810 it can be used to prime the built-in GPS for faster lock times, and get a lock within buildings etc.
Skyhook make money licencing their technology to OEMs etc., however their SDK is downloadable and, once you get through the signup process, you find they've got ARMEL binaries for Maemo 3.1 (i.e. OS2007).
Unfortunately, I don't have an OS2007 device, and trying to get it working on OS2008 ultimately resulting in a segmentation fault. They've yet to reply to the email I sent asking if they've got a Maemo 4.0 (chinook/OS2008) SDK available.
However, this is promising for two reasons: 1) they're aware of Maemo; 2) it might be something Nokia is looking at licencing.
All of this could be tied together with GeoClue and at some point we might take advantage of location-based services. That'd be a cool day.