Is there a way to refine my "current location"? I recently purchased the Day One journaling app, and it geotags my posts. However, it really bugs me that it sets my home location as the wrong address. It's close, it's within a few hundred feet, but the address isn't quite right.

Is it possible to "calibrate" at a given location? That is, if I'm on 123 Main Street and it thinks I'm on 200-300 Main Street, can I tell OSX "If you think you're at 200-300 Main Street, you're actually at 123 Main Street"?

That'd be useful to me; I'd get more precise directions and more precise posts in Day One.
Register your router's MAC address with Skyhook and enter your correct latitude/longitude coordinates.
http://www.skyhookwireless.com/howitworks/submit_ap.php

After a few days, your location should be correct in any website or app that uses Skyhook's database, which is fairly ubiquitous.