Apple - Is there a standard uninstall procedure on Mac OS X?
Remember that (most) Mac OS X apps are installed self-contained; i.e., you simply drag a copy of the *.app folder into the Applications directory of your choice.
Once reason for this is to simplify the uninstall - delete the app folder; simple.
None that I know of (as advertised by Apple, I mean). I found this on my bookmarks: http://www.thexlab.com/faqs/uninstallingapps.html, which might give you a better idea of what to do before and after installing applications.
There are a few apps that take care of this too like: AppCleaner which tries to find the documents and settings the application uses (though it's debatable how efficient/reliable this apps or any app of this nature really are)
The vast majority of OS X programs are actually bundles; if you open the terminal and navigate to the application folder, you'll find that your applications are actually directories (folders). Inside are various libraries, executables, resource files, etc.
To uninstall you usually...usually...just drag the application to the trash and empty it. Then do a search from the Spotlight textbox (think it's a dropdown from the magnifying glass in the corner) and look for the application name to find any .plist files in the library folder(s); those are the preferences. You can drag and drop those into the trash as well. Then the application should be gone.
I say usually because some applications did use installers when you put them in, and sometimes those installers can when re-run uninstall the program. The majority, though, can be eliminated as described above, especially if you installed it by dragging it to the application folder in the first place.
If you screw up somehow you could always just reinstall the application and look for a README file in the installer DMG volume. I've seen a lot of applications that come with a README just to tell you to drag the application to the trash to uninstall it.