I've read the WordPress tutorial and http://www.binaryturf.com/run-multiple-sites-wordpress-30-separate-domains/ and it seems I need to use subdomains and wildcard DNS to use WordPress Network on multiple domains.
Unfortunately, my host doesn't support these. Is there some way to use domain mapping (via a plugin or htaccess) and subdirectories to use one WordPress install across multiple domains on shared hosting. e.g. could I make http://primarysite.com/ have one blog and have another blog on http://primarysite.com/seconddomain which redirects to http://seconddomain.com/?
Any tips would be greatly appreciated.