So just this evening the sound has stopped working through the normal handset usage of my iPhone. If I put it on speaker it works, if I put in the headphones, it works, and all of the click sounds work (unlocking, locking, typing, etc). Because the click sounds work I know it's not that the headphone jack needs to be reseated/contacts cleaned (although I tried, I did have that problem a few months ago). So what's going on? It is only that the speaker doesn't work when I'm in a call in handset mode, or trying to listen to a voicemail in handset mode. The speaker works in all other situations.

Any ideas? Should I just take it to an Apple Store?