PECompact compresses Windows executables significantly, while allowing them to be run as normal. You can compresses code, data, import/export table, and selected resources. Section merging and resource data restructuring are also supported. It trims, optimizes, and realigns the PE structure while preserving shell icons and version information, or any other resources you chose to leave uncompressed. Uses its own JCALG1 compression, which offers decent compression speed, great compression ratio, and extremely rapid decompression.

Version 2.28 is shipping in June, 2004.

http://www.collakesoftware.com/pecompact.htm