Dropbox on OSX now tries to install a contextual menu item.
This slows down the system under Mac OS X 10.6 and lower.
If, like me you don't want this and want to have the freedom to turn this off:
First, Quit Dropbox from the menubar icon.
Remove or rename the following file to something else (otherwise it'll get put back in)
/Applications/Dropbox.app/Contents/Resources/DropboxHelperInstaller.tgz
Then, navigate to /Library/DropboxHelperTools and delete everything in there.
To undo this, rename the file back again at: