It wasn't that long ago that our notion of computers of the future involved talking to them: "Print this document, Jeeves." I haven't heard as much about this in the last few years, perhaps because typing is becoming a fundamental part of literacy and doesn't seem as onerous as it once did.
Perhaps we've also realized that it would be really darn annoying. I just moved offices (one door down) and am now in a room that has five to eight people working in it at any given moment. It's never silent, but it would be a whole lot louder if we were all dictating our writing, telling Excel to do sums, and hollering at Word not to screw up mail merge.
The notion of speech-based interaction with computers hasn't entirely disappeared, but it tends to be relegated to science fiction where the computers have a personal relationship (not to mention a personality) with the protagonist - think Kevin Spacey as the computer in Moon. It's worth noting that in Moon there is no one else around to be annoyed by the chatter; in fact the computer is an important social support for the protagonist.
This is one of those cases where predictions about the future got it wrong not because the technology couldn't be developed but because the basic technology was too successful. Talking to computers makes sense when they are important but rare; in a world where the average iPod is more powerful than HAL, we can't have everyone going walking around and mumbling, "Play Maroon 5."