It's messy. Even following the steps given by Microsoft at http://support.microsoft.com/default.aspx/kb/928091 are rarely followed. In fact the steps are Greek to most.
I'm going with no. Too tough.
I have Office 2003 running well on my machine at home. Need to learn how to use 2007 for work purposes. Is it possible to install 2007 any way on my home machine in such a way as not to interfere with the running of the 2003 version.