Hi,
I've just installed Chrome on my USB. When I try to run it in the office (behind a proxy and with lots of security in place) nothing happens. I checked the app folder and I noticed a file that would like to make additions to the registry. As this is not allowed within my laptop, I understand that nothing happens, but I assume this is not quite correct? Portable means no changes to the registry, or am I mistaken?

You're right "Portable", using the strict definition, means : no registry entries, no local files created, never.
http://en.wikipedia.org/wiki/Portable_application

They are called "natively portable" applications, and Liberkey as any other portable suites tries to integrate the most of such applications in their catalogs.

But to be honest even if we are doing the best to use such applications, some of them are not "natively Portable" but "Transportable" indeed. Chrome is one of them.

Those "transportable" applications are launched using the Liberkey Portabilizer which is able to save and restore their running context (the ones which have been identified by us or by members). It means, just before running the native .exe (not portable !), it rebuild the registry and/or files entries in order to use it during the run. Then, after application closure, the Liberkey Portabilizer saves and deletes the entries from the system to the Liberkey application folder in order to restore the system like it was before the run and to be able to restore it for the next run.