I work on a variety of projects for a variety of clients.  Some of them don't use any Source Code control (in which case, I do my best to convince them it's needed), some use SourceGear Vault, some use SourceOffSite or SourceSafe and some projects even use CVS.

One of the most frustrating things to deal with is opening a project in Visual Studio, only to find that the default SCC provider is not set correctly.  I certainly wish this were stored (at least in the case of VS.NET) in the solution file.  Anyway...I used to use a couple of .reg files, but this got to be a real PITA, so a year or two ago, I created a small app to make the switch quick and easy.

SCCSwitcher is a small, stand-alone program that allows you to quickly and easily change your default SCC provider.

SCCSwitcher is freeware.