The right tool for the job

I have a project and I'm hoping that you guys can help me figure out what the easiest way is to accomplish this. What I want to do is basically set up a blog, but I want to be able to tag each post with a physical location (longitude and latitude coordinates). I'm hoping that whatever tool I'm using would then make it relatively straightforward for me to do things like show all the locations on a Google Map or sort the posts in order of their distance from a certain place, generally be able to hand this post meta-data off to other bits of code.

So far I looked at things like WordPress and Drupal (I might be totally looking in the wrong places) but they don't seem to be able to do what I need. (Then again, I didn't spend too much time playing with them and their various plug-ins.) I'm not opposed writing my own code, but I figure if I need to modify one of these applications' cores, it would just be easier to write my own crude content management system.

Any ideas would be appreciated. Thanks.