> It would be nice to have an option to create all links in 
> the mirrored site as local links, even if they reference 
> links included in the project.  This could be 
accomplished 
> during or through a conversion process started after the 
> mirror was completed.

This is not an obvious option to implement, for one reason: 
collisions and name fixing. To summarize, you can have 
diferent URLs having the same file location (foo.html and 
FOO.HTML, for example, on case-insensitive filesystems), 
and URLs sometimes are changed to fit their type (foo.cgi -
> foo.html or foo.gif depending on the case), and this 
requires remote file testing.

> My largest problem is the MD5 hash of query strings.  It 
> would be nice if an option was available to convert 
> invalid filename characters to an acceptable replacement 
> (? to @, etc).  This way, an Apache rewrite rule would be 
> easier.

Tuning the naming system is possible, using callbacks, but 
requires some coding. You can have a look at the python 
module integration:
<http://www.satzbau-gmbh.de/staff/abel/httrack-py/>

Which allows you to wrap naming callbacks, and others.