Thanks to a pointer from Niko Sams, I seem to have gotten my configuration issues with Apache and mod_rewrite sorted out. What finally worked in the .htaccess file was the following:
RewriteCond %{http_host} ^(.*)\.karasu\.local
RewriteCond %{request_uri} !^/+(karasu\.local)/?
RewriteRule ^(.*)$ http://karasu.local/%1/$1 [L]
Thanks So, now "http://karasu.local" serves me /var/www/index.html and "http://live.karasu.local" serves me /var/www/live/index.html. Cool.
Okay, off to try to debug storytlr's Twitter notifications!
