Mine

sh-3.1$ cat rorblog.common
#ServerName rubyonrailsblog.com
#DocumentRoot /var/www/html/uncled/new_ror_blog/public
#
#  <Directory "/var/www/html/uncled/new_ror_blog/public">
#    Options FollowSymLinks
#    AllowOverride None
#    Order allow,deny
#    Allow from all
#  </Directory>

  RewriteEngine On

  # Make sure people go to www.rubyonrailsblog.com, not rubyonrailsblog.com
  RewriteCond %{HTTP_HOST} ^rubyonrailsblog.com$ [NC]
  RewriteRule ^(.*)$ http://www.rubyonrailsblog.com$1 [R=301,L]
  # Yes, I've read no-www.com, but my site already has much Google-Fu on
  # www.blah.com. Feel free to comment this out.

  # Uncomment for rewrite debugging
  #RewriteLog logs/myapp_rewrite_log
  #RewriteLogLevel 9 

  # Check for maintenance file and redirect all requests
  RewriteCond %{DOCUMENT_ROOT}/system/maintenance.html -f
  RewriteCond %{SCRIPT_FILENAME} !maintenance.html
  RewriteRule ^.*$ /system/maintenance.html [L]

  # Rewrite index to check for static
  RewriteRule ^/$ /index.html [QSA] 

  # Rewrite to check for Rails cached page
  RewriteRule ^([^.]+)$ $1.html [QSA]

  # Redirect all non-static requests to cluster
  RewriteCond %{DOCUMENT_ROOT}/%{REQUEST_FILENAME} !-f
  RewriteRule ^/(.*)$ balancer://mongrel_cluster%{REQUEST_URI} [P,QSA,L]

  # Deflate
  AddOutputFilterByType DEFLATE text/html text/plain text/xml application/xml application/xhtml+xml text/javascript text/css
  BrowserMatch ^Mozilla/4 gzip-only-text/html
  BrowserMatch ^Mozilla/4.0[678] no-gzip
  BrowserMatch bMSIE !no-gzip !gzip-only-text/html

  # Uncomment for deflate debugging
  #DeflateFilterNote Input input_info
  #DeflateFilterNote Output output_info
  #DeflateFilterNote Ratio ratio_info
  #LogFormat '"%r" %{output_info}n/%{input_info}n (%{ratio_info}n%%)' deflate
  #CustomLog logs/myapp_deflate_log deflate