> When I tried out httrack, it creates links that do not 
work
> if the whole mirror is moved elsewhere. (they include the 
> whole path to the c: drive files in each link).

??? Are you sure? Generally this is IE/Mozilla which shows 
the complete file:// path, BUT httrack will NEVER 
generate "file://" links itself, ONLY local relative links 
OR external http:// links. Can you check the HTMl code, too 
see if links are okay?
> Is there any way to make the local copy portable?
The site should be always portable, whatever the location 
is (local drive, cdrom, dvdrom, remote site, palm pilot..)

If is does not work on certain sites, it is either a huge 
bug in the engine, or a problem with the remote site 
(javascript?) ; so please provide bogus URL and more 
details, thanks!