Is there a way (app, configuration, etc) that will allow me to accept e-mail calendar requests sent to a POP3 account? The request could be iCal or could originate from Exchange or Outlook. Once accepted, I would like them to be added to my calendar.
Yes, support for this is native in Android.
I have an Exchange account added to my phone (Settings > Accounts & Sync > Add account). Once I snyc'd email and calendar I was able to receive meeting requests through the Mail application, accept them, and then see them show up in my calendar with a different color. The way Google handles Exchange is really sweet.
So I played around a bit and here is what I found. From the gmail app on the phone you cannot accept appts. But, not sure how it works with iCal and such, I just sent myself a meeting notice from my Exchange Outlook calendar to my gmail account. I signed into Gmail from my computer, got the invite, I clicked yes I am attending, and it now shows on my calendar.
So from the gamil app it appears we cannot accept invites but from a computer we can. :(
It's a known problem in Android system. You should use a third party app. I know (and recommend ןא!) the 'ics 2 android' application. You can download it from google market: ics 2 android