localizable.strings editor for translators

There is an online tool for this called Gengo String: http://gengo.com/string/about/

If you are happy to do some file conversion you could use Pootle to host you own online translation, that eliminates most of the techie overhead and the need to install software.

The conversion would be using prop2po to convert your strings files to PO files that Pootle can directly use. But the trade-off for non-techie users can be worth it.