Sharepoint on port 80? and computer name

Hi i have two issues.  

 1.  I installed sharepoint services on my server it works fine,  except the
virtural server port has to be anything other then 80.  When its on port 80 I
get error when trying to start:

"The process cannot access the file because it is being used by another
process”

The win2k3 server isn't running anything in terms of websites that I know.  One
suggestion was that my blackberry ent software was hogging the port. 
Regardless, is it possible that only one application can use port 80?  I am not
a iis guru, but it seems like multiple apps can use port 80  Also, I've been
told the firewall isn't blocking it. (hence blackberry useablilty)

This leads me into my next issue.  Because of the port alteration users have to
pass it on the URL line of a browser(http://host..: 8003)  I would really like
to make the user experience as easy as possible, which also means the site name
is easy to remember.  

Which brings to my computer name question.  Not only does the port name bug me
so does the server name.  It is an non-intuitive name and want to change it
without changing the machine name.  Somehow through IIS ?  I want to have
something like...http://mysharepoint/sites/  not http://203-map/sites

In a nutshell I have full control of the IIS components, but anything outside of
that sysadmins get a distressed look.  What can I do?  OH and last 1 thing this
server is on the internal network only so I can raise "a little" hell.
   

 Thanks in advance!!