Changed it so the ssh port is configurable as well. (As I ran into the same issue already described at https://github.com/imathis/octopress/issues/30 )

Rakefile

@@ -5,6 +5,7 @@ require "stringex"
 ## -- Rsync Deploy config -- ##
 # Be sure your public key is listed in your server's ~/.ssh/authorized_keys file
 ssh_user       = "user@domain.com"
+ssh_port       = "22"
 document_root  = "~/website.com/"
 deploy_default = "rsync"
 
@@ -218,7 +219,7 @@ end
 desc "Deploy website via rsync"
 task :rsync do
   puts "## Deploying website via Rsync"
-  ok_failed system("rsync -avz --delete #{public_dir}/ #{ssh_user}:#{document_root}")
+  ok_failed system("rsync -avze 'ssh -p {ssh_port}' --delete #{public_dir}/ #{ssh_user}:#{document_root}")
 end
 
 desc "deploy public directory to github pages"