After getting fed up manually creating device packages for EAGLE, the following tool was created. It allows for the automatic creation of many SMD packages. Here are some examples:
The tool just needs some values entered, which can be obtained from component datasheets or this very good website.
This document eagle-cad-smd-drawing-tool.pdf contains all instructions on how to use the tool. The Windows executable is available here: smd_tool.zip (no installer, just place the file at a convenient place and then launch from the Windows command prompt. The PDF document contains all details).