As a vi user who codes in a GNOME environment with sloppy keyboard habits (you'd think there wouldn't be that many of us, but... surprise!), I hate the GNOME default of having F1 bound to the help menu. I'm constantly hitting F1 when reaching for ESC, so I regularly get annoying help windows popping up.
For a long time, I assumed that it was the top-level GNOME help document -- you know, like "how to use GNOME." I'm still not sure if this was ever the case. But today, I noticed that it's actually showing me the help file for GNOME Terminal. I scoffed that I would actually care to read the help file for my terminal emulator.
The irony is that if I had *read* that annoying help file, I might have actually found the answer to my problem. You can disable it (and set a lot of other nice shortcuts) under Edit | Keyboard Shortcuts.