If you need translations for your site but translation packs are not fully translated, then inline translation
is very nice feature.
1) Admin / System / Configuration / Developer
Allowed IPs (comma separated): Your Ip (or empty)
Enable for Frontend: Yes
Next step is to go to the frontend and select desired language from the dropdown.
Red rectagle strokes around text will apear and when you hover it the little book icon will apear.
Just click on the icon and insert desired text. Check "Store View Specific".
All translations that are been made by inline translation are stored in database in shop_core_translate table.
If you move magento from server to server you need to export this table and import it when you configure your
mysql database on another server.
Strings that are translated with inline translation as an option are stored in database->core_translate table.
Delete the string from database if you want to revert.