Localization optimizing issue

Hello, there:
   My website would like to offer both Chinese and English version,
and "Localization" plug-in is utilized. However, by the site growing
up, I am more and more realizing that the translation file is a mess
   The reason:
1. for each word or phrase which needs to translate between, we have
to modify the string, e.g. from "hello" to "_(hello)" both on
controllers and views, other non-technical guys are hard to help me,
because they have to look into the source code.

2. All translations are stored in to several .rb files under LANG
directory, this is also hard to revise and scale later.

   So, I come and ask you guys, how do you arrange and manage your
translations for your site? Any comments are truly welcome!