You can:
Edit Health and Armor, set them up to 1000.
Edit Weapon Slots and Ammo's, select from within all gta4 weapons and assign ammo.
Set Money to any amount you want/enter.
Change Game Time (Day, Hours and Minutes) - So no more late to appointments, ever daytime for stunts.
Teleport the player (only when standing on foot) to any location within gta 4.
Set Player Invincible (ie God Mode)

Teleport Locations Tab has also a full-sized GTA4 Map for detailed teleporting. Red Box shows player's current location (read from gta iv). The blue box is manually set location by clicking on the map with mouse, or entering the value in the textboxes. The teleport function works only when player is on foot.
You can also simply enter the new location to the CPlayer x/y/z textboxes and teleport the player to the new location. The buttons to save the locations into confing file etc does not work yet.

This is a Net.2 executable. no need to install, does not write into any files or registry.

You will also need the XLive.dll Wrapper from Rick to make it work:
http://blog.gib.me/2008/12/20/hacking-gran...to-iv-part-iii/

The XLive.dll Wrapper and GTA4Center works in offline mode only. So no multiplayer support.

cheers, and happy playing...

Important:
1. Should now work with vista, I cannot test, but coded the necessary bits and pieces (do not forget to enable DEP)
2. Options to auto-fix/limit health + armor does not work yet. You will need to manually set the desired values.
Instant-death would still apply for falling down from top of a building,
or when sitting in an exloding car.
3. You can only edit the game time and special flags if you do not have the xlive.dll wrapper from Rick (link above)
4. Again, if you cannot edit armor, health, or weapons, but can change game time, you need to use the xlive.dll wrapper!! 