This works by accessing the USPS web site, so one needs to be online for this to work. Since the code parses the HTML code, this breaks whenever the web site code is reorganized, which seems to happen every other year or so, but can be fixed by adjusting the regexp (which may take a bit of fiddling). The code is in TCL, so one needs to use a TCL-enabled version of Vim. The following should go in your gvimrc file: and this into utilities.tcl: