Source available @ https://github.com/dustindavis/ConnectionStringManager

Updates:

v1.2 

- Fixed a bug that caused visual studio to crash when trying to change a config file that is set to read only.
- Fixed the refresh button

Quickly and easily manage all connection strings in a solution from a single location.

With ConnectionString Manager, you can 

• Test connection strings
• Navigate to config files quickly
• Add and Remove multiple connection strings to multiple configs at once
• Save connection strings for later use in other projects

 Don't waste any more time manually working with connection strings, try ConnectionString Manager and get back to more important things!

Features

Quickly View all connection strings in a solution

When the extension is ran, it scans the entire solution and extracts all connection strings from the configuration files and displays the project, config file, connection name, connection string and the connectivity status.

Test one or all connection strings
Quickly validate connection strings with a single click, without leaving Visual Studio. Testing can be done from almost any dialog.

Quick open
Quickly open the host configuration file for any connection string. No more hunting through solutions and projects to find the configs.

Add, Edit, Remove connection strings
Add, edit and remove connections strings all from a centralized utility window. No more hunting for and jumping between config files to make edits.

Save connections for later
With the saved connections feature, you can store common connection strings for use in other projects.

Swap connection strings
Quickly change a connection string to a saved connection string quickly with the quick list

Add multiple connection strings to multiple configs at once
New and saved connections can be added to many configuration files with just a few clicks. No more copy & paste. Enter the new connection string data and/or select one or more saved connections, then choose which configs to write them to.

More info at http://www.programmers-unlimited.com