As I yet posted this is a little tool to help with common tasks to maintain resource files. Recently I started to use the famous StringResourceTool MS used within the Enterprise Library and it is way cool! Worth to have a look if you start a new project from scratch.
But stop! You can now migrate existing project(s) to use the the StringResourceTool by the little help of the DiffPatchResources tool! Just download and copy it to a folder you configured to be found if you start a windows command line (%PATH% variable). Then use the new option -s to create the .strings file out of your existing main .resx file and save all the hand writings...

Update: to get the StringResourceTool run in VSIDE 8.0, add these settings to your registry by help of a .reg file with content:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\8.0\Generators\{FAE04EC1-301F-11D3-BF4B-00C04F79EFBC}\StringResourceTool]
"CLSID"="{1D47CA76-5AF1-4152-8106-08140FF9886E}"
"GeneratesDesignTimeSource"=dword:00000001
@="Microsoft Data Warehouse String Resource Generator"