If the game doesn't need game data installed ebootFIX is better, just put the contents of USRDIR in hdd0/game/"gamename"/USRDIR.
Keep in mind that compatibility is still only about 60-70%BD2HDD has better compaibility though but it's not for everyone
THIS METHOD PUTS THE GAME ICON ON THE PS3'S GAME MENU AND AFTER INSTALLATION YOU DONT NEED A JAILBREAK TO PLAY IT BECAUSE ITS SIGNED THANKS
TO THE AWESOME APP BY BrownMuffin called "Pkg Builder" and of course all the hard work from failoverflow and geohot.....

USE THIS TUTORIAL IF A GAME YOU WANT TO TRY REQUIRES "GAME DATA" TO BE INSTALLED.....
1.First Download "Pkg Builder" by BrownMuffin from here: http://www.megaupload.com/?d=81QDH084
Remember to run Pkg Builder in Adminsistator mode so it can write files OK. Just right click it
In Step 2 of pkg builder, if you don't alter game path put the contents of the games USRDIR folder in hdd0//game/"gameID"/USRDIR.
Or if you want to change it make sure the name has 8 letters/numbers and all in CAPS, then copy over the games USRDIR folder (not just the contents) to hdd0//"GAMENAME", without quotes.

You need to do the following steps to make the PS3 recogrize the FALSE folder name for the game you want to install to XMB
Quick Guide: Create REAL.pkg
Replace files, alter game ID and game name of PARAM.sfo and create DUMMY.pkg, install both .pkg's
Empty hdd0//game/DUMMY/"contents" and fill with hdd0//game/REAL/"contents"
Delete REAL icon from XMB. Or keep reading
2.1.a. Use PKG Builder to create the (REAL).pkg for your game.
b. Then to make the DUMMY .pkg replace the EBOOT in PKG Builder's GAME/USRDIR folder with the original because the first one has been modified and is now useless.
c. Then use PS3SFOedit to change the game ID to eg. for BLES00001 change to BLES00002, just change the last number so they're together in file managers. And change the game name so you know which icon is which in XMB
d. Create the DUMMY.pkg and install both .pkg's
3..a. Use your file manager to delete the contents of the DUMMY folder and copy over the contents of the REAL .pkg's folder. eg. hdd0//game/BLES00001
b. Exit to XMB and delete the icon with the REAL name, after one play the one with the DUMMY name will correct itself with the REAL name.

If it doesnt work try just using the DUMMY.pkg or change the USSRDIR location eg. alter game path/ dont alter game path.

Games that are working that need Game Data installed:
Resident Evil 5 Gold Edition
Lost Planet 2
The Orange Box (but a jailbreak dongle is needed)
Dead Rising 2....... This one was a bastard to get working so heres the pkg and instructions
Dead Rising 2 XMB install: http://www.megaupload.com/?d=E3TGNEZB
Vanquish works but automatically uses an alternate folder name so no need for the above method
Ghost Busters

Games that are working that dont need Game Data installed:
Tomb Raider Underworld
Call of duty Black Ops..... Intsall Package http://www.megaupload.com/?d=V0M24EAH
F.E.A.R. 2 BLES 00464 (doesn't work on 3.55 waninkoko v2, only option is multiman 1.16+/ highlight game/select+x)
Timeshift (saving and using save files is buggy)