Remove "wordpress" from permalink?

Greetings. I’ve got WordPress 3.4.1 installed on an Ubuntu 12.04 system. The
Apache document root for this system is:

/var/www

and I’ve got my WordPress installation in:

/var/www/wordpress

I used the Dashboard to modify the permalink structure and got the following
.htaccess file:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /wordpress/
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /wordpress/index.php [L]
</IfModule>

# END WordPress

This does give me nicer permalinks, but the URL’s have “wordpress” embedded in
them, as:

http://my.domain/wordpress/nice-page-name/

I’d like to remove the “wordpress” string, as:

http://my.domain/nice-page-name/

One way to do that would (probably) be just to dump all my WordPress stuff
into the web server’s top level:

/var/www/

and there’s no reason I couldn’t do that in this particular case, as I have no
plans to have anything but WP running on this site. But it seems ugly.

I thought it might be possible to achieve the same effect by tweaking the
.htaccess file. I tried just omitting “wordpress” in the file, as:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

but all that got me was “page not found”.

Is there some way to do this, other than moving my WP stuff up one level in
the directory tree?

Thanks.

— Mike