The .NET standard of prefixing an interface name with an I seems to be becoming widespread and isn\'t just limited to .NET any more. I have come across a lot of Java code that u
For .NET, Microsoft's Framework Design Guidelines book absolutely recommends it, and yes, it is very much standard. I have never seen it done otherwise, and to create a new convention would only serve to confuse people.
I should add that I dislike Hungarian notation too, but this and the case of prefixing class variables with an underscore are good exceptions to me, because they make code so much more readable.