Is it possible to use C# 5 async features in Linqpad snippets? Does anyone know of any hack/beta which allows you to do it?
Installing the async CTP should be enough - async code should compile in LINQPad (although the Intellisense will show red squigglies). I'll look at dealing to the red squigglies in the next beta :)
You will have to add a reference to asyncctplibrary.dll, as in VS.
Update: the red squigglies and autocompletion has been dealt to in the latest beta.