A lot of people sing the praises of programs like Notepad2 and jedit because they offer syntax colouring for pretty much every language under the sun, which is great for toe-dipping exercises in things like Haskell or quick programs you'll manually compile later.
Visual Studio doesn't offer this functionality by default. Has anyone written an add-in for VS that adds the ability to edit any text file and get syntax highlighting for it? It goes without saying that integration with a compiler won't be needed, nor will debugging or any kind of "intelligent" processing like IntelliSense.
Although, come to think about it, integrating the compiler into a simple build system with the "Errors" and "Output" window would be nice.