I've been asking for this for at least three years, too. We need the ability at the Host to initiate a Chat. Now, you have to open a doc and type a message in it to get the Remote/Guest user's attention, who can then initiate a GoToMyPC Chat from their end. How about showing a Chat option for the Host user when right-clicking the MYPC icon in the bottom-right of the screen? This doesn't seem like a hard feature to add, since a Chat function with a host window already exists in the software.
Plus, the title of this thread is wrong. Shouldn't it be Start a chat FROM Host computer? You can already start a chat TO the Host. Unless my idea of Remote/Guest vs. Host is backwards. And Glenn's statement "as that is when we know someone is present at the Host" seems to be a moot point. We can initiate a chat to the Host whether someone is actually there or not. What difference does it make? Being an old guy, I'm very aware I could be missing something here!