Headhunter wrote:

I want to install Outlook 2003 on an external hard drive and run it
from there...

It can't be done. While much of Outlook's files can be placed there, may of
them cannot. There is no such thing as an Outlook you can carry with you
that way (without a Tablet PC or a PDA).

I'm hoping I can do the following: use email for my
personal accounts (yahoo & gmail), contacts, calendar, and tasks. I
also want to sync to my smartphone via activesync. Is this possible?
Also, once I unplug my hard drive from my laptop, will there be any
trace that I used Outlook?

Most Windows-based applications, especially those from Microsoft, leave
tracks all over - in the Windows folder, in the System32 folder, in the
registry, and so on.
--
Brian Tillman