UniExtract is another one. But none of them open all types of installers afaik. Another possibility for msi is msiexec /a PathToMSIFile /qb TARGETDIR=DirectoryToExtractTo. Actually before installing anything at all I usually try some of these to get a portable app. It's amazing how many installers out there are bascially just automatic single-directory extractors which also happen to add some regsitry entries.
(Incidentally, many people don't know that 7-zip can extract installer executables and various other formats too...)