Loki, the location aware browser plug-in updated its service for use on Macs and mobile phones earlier this week. Previously, Loki users were relegated to Windows. The new Mac version of the Loki is in fact not a toolbar like its Windows counterpart. Instead, users get contextual menu support, and pop up notifications of third party sites that have been Loki-enabled using the developer API. Loki's creators insist that people who use these services enjoy having them available all the time, just not taking up their browsers real estate--which I agree with.
The mobile version works with any handset running Windows Mobile and doesn't require your phone to have GPS. In fact, Loki doesn't work like that. It uses your phone's built-in WiFi and several access points to triangulate where you are, similar to how the police track down bad guys using cell phones in movies and TV shows.
Services that have developed Loki integration using the API give users the chance to automatically send their location information and use on site services. One site that's done this is Socialight.com, which lets you create and explore sticky notes on maps.
One of the things I really enjoy about this service is that it's geared towards road warriors. I gave it a whirl earlier this week at the Where 2.0 conference, and it worked surprisingly well (better than Rafe's experience). Here at the office; not so much. For driving directions I'm still more comfortable feeding a service my exact address (which you can do with Loki), and if it were a life or death situation, I'd probably feel better with GPS. Still, for people with neither GPS or an exact street number, this is handy technology.