There are "universal wrappers" that attempt to do extra work to try to make non-portable applications work in a portable fashion:

<ul>
<li><a href="http://portableapps.com/development/projects/registry_rapper">Registry Rapper</a>
<li><a href="http://portableapps.com/node/6924">PortaLaunch</a>
<li><a href="http://www.portablefreeware.com/forums/viewforum.php?f=10">JauntaPE</a>
<li><a href="http://sourceforge.net/projects/x-launcher">X-Launcher</a>
</ul>