There's actually no need to "black hat" or sideload the app. If you can't find it in your Google Play search, or if clicking on "Download" from the http://facebook.com/home page lands you in the Google Play install page but it says your device isn't compatible, then don't worry, there's another way.
I have a Sony Ericsson Xperia P and I googled hard for a solution; then I read that Facebook pushed an update recently which (in addition to adding support for 2 more phones) let's you "Use Home anyways". So how to install Home in the first place, you say? Head on over to 1 Mobile Market (http://www.1mobile.com) and download their app. Once installed (make sure you enable "Allow unknown sources" in your phone's Security settings), look for Facebook Home in the 1 Mobile marketplace and install (again, make sure you can install from unknown sources). It should run automatically once installed and you should see the "Use Home anyways" option.
Facebook Home the legal and official way. Worked great for me! Enjoy!