Not that I think this is accurate by any stretch, but what would account for the massive jump in "Other" in 2005. Smart phones like Nokia before iPhone + Android?
I wondered the same thing, at first glance I thought that was GOOG's slice of the pie - 4 different shades of blue doesn't make for a good contrast. Then I decided it had to be RIM/Blackberry.
Wow. RIM hadn't even entered my thought process. Funny how quickly things change.