I remember one three-week on-site training gig that had me staying in a new town every night. One morning, I confess that I had to look for a local phone book in the room to remember where I was.
If only I'd had Loki, I would have been in much better shape. This clever little tool bar calculates your exact location by triangulating from the available wifi networks. (Look here for a how-it-works description from Skyhook Wireless, the company behind Loki.)
The Loki tool bar takes the information on your location and lets you identify local stores on Google or Yahoo Maps or see a map of nearby wifi hot spots, info on gas prices in your neighborhood, nearby apartments for rent... even local geocaches.
So, now that I have Loki, I can roll out of bed in some strange hotel, fire up my laptop and let Loki to tell me where the local Starbucks is, what the weather will be, which local FM stations play classical music, and how bad the traffic is. It can't tell me why I'm there or who I'm supposed to be meeting, but I expect that enhancement any day.
The one complaint I have is that Loki doesn't (yet) work with FireFox v3, although it's fine with Firefox v2, IE and Safari.