Microsoft and Palm have been building full-face touch-screen mobile devices since the late 1990s. Full-face Touch-screen PocketPC phones started coming out in 2002ish.
Yes, they were resistive rather than capacitative touch-screens. That wasn't because it didn't occur to anyone to use a capacitative touch-screen before Apple, it was because the technology wasn't mature enough before around 2006/7. And if even you want to make the (silly) argument that whichever manufacturer happens to be the first to bring out a full-face capacitative touch-screen phone can somehow claim to have invented the concept, that honour goes to the LG Prada.
