I was trying to learn a bit about MSBuild today and how things get built in Visual Studio, and I came across a cute little hack. I may be the last person in the world to discover it, but I still thought it was neat.
If you go to:
around line 145, and delete these two lines:
and around line 166, change these two lines:
ToolPath="C:\Program Files (x86)\Mono-2.2\bin"
(your ToolPath may vary)
when you build your C# projects in VS2k8, it will build them with Mono's C# compiler "gmcs" instead of Microsoft's "csc" compiler.
(If you try this, you should of course backup your Microsoft.CSharp.targets file.)