The speaker in my Acer Liquid E stopped working 2 weeks after warranty ended. At first, I thought it was a software glitch because of some app, so I reinstalled the entire Android 2.3 OS on the mobile with LiquidNext (official website). I got amazing new capabilities with that OS ROM, but no speaker.
Hardware problem then. The Wan Chai people in HK wanted a hefty sum just to look at it, Acer wanted even more. Seriously? for a lousy mobile speaker...
So, I took my Acer apart. First time I ever opened up a mobile, and I didn't realize just how challenging that is. After playing around a bit, I was somehow able to reach the speaker. I then looked up the part, and saw that HP iPaq Voice Messenger looks similar (4.9US$ + 6US$ delivery). I also saw that this was discussed on XDA developers.
I ordered it in, waited a few days, got the package, dismantled the Acer again, patched the new speaker inside, prayed a bit to the mobile Gods, and .... what do you know - speaker works.
I'm awarding myself a geek medal.