That was a long time ago, and I think it's discontinued. Gnome Mobile and Embedded Initiative hasn't had an update presented at GUADEC or any other major FOSS conferences in 8 years.
Maemo?
Before they switched to Qt, Nokia had extensions to GTK called Hildon.
Qtopia?
That's QT not GTK. Also QT is still used while the toolkit I'm thinking of isn't.
You might be talking about Enlightenment (not dead yet) or the openmoko gtk ui, though I forget its name too.