Infamous 2 Cheats

Nothing Can Bring Me Down (Bronze): Stay off the ground for 130 meters.
Return to Sender (Bronze): Send a Helicopter's rockets back at it using any Blast ability.
Vehicular Manslaughter (Bronze): Defeat 25 enemies by throwing cars at them.
Take Them For A Spin (Bronze): Hit at least 6 cars in a single Ionic Vortex.
Shock and Awe (Bronze): Thunder drop into a group of 5 or more enemies.
Thunder Flop (Bronze): Thunder drop from the highest place in New Marais.
Head Hunter (Bronze): Use the Precision ability to rack up three head shots in rapid succession.
Discerning Taste (Bronze): Take down a street performer who is imitating a statue.
I'm As Shocked As You Are (Bronze): Defeat an enemy or civilian by stepping in water.
Don't Fence Me In (Bronze): Climb a chain link fence and rejoice.
Express Elevator (Bronze): Ascend 50 vertical launch poles.
Heavy Hitter (Bronze): Use your Ionic Powers 30 times.
Matching Set (Bronze): Unlock and purchase a power of each type by performing stunts.
Level Up (Bronze): Create a new mission using the UGC level editor.
UGC Curious (Bronze): Play 10 user-generated missions.
UGC Veteran (Bronze): Play 25 user-generated missions.
Trail Blazer (Bronze): Play 5 user-generated missions under the Newest filter.
With Great Power Comes Greater Power (Silver): Unlock and purchase all powers.
Shardcore (Silver): Pick up 50% of blast shards scattered around New Marais.
Fight the Good Fight (Silver): Unlock the good ending.
Forging Your Own Path (Silver): Unlock the evil ending.
Land Lord (Silver): Take over the first island in New Marais.
It's My Town, Now (Silver): Take over the second island in New Marais.
Well inFORMED (Silver): Collect all Dead drops.
Arch Villain (Silver): Earn full negative Karma.
Incorruptible (Silver): Earn full positive Karma.
Pain Builds Character (Gold): Finish the game on hard difficulty.
Just One More (Gold): Pick up all the blast shards scattered around New Marais.
inFAMOUS 2 Platinum Trophy (Platinum): Collect all other inFAMOUS 2 Trophies

Buy Powers for Free
Any powers you buy during a UGC mission will not reduce your available XP. So, just create a blank UGC mission, start playing it, upgrade powers and then quit mission. You will have same amount of XP as you had before buying powers but all powers will be unlocked.

Fast Travel
Using a glitch with the User Generated Content editor, you can move Cole anywhere in the game world.

1. Start the game and open a blank mission using the editor.
2. You will see a circular marker on your screen. You can move around using the left stick and move up and down with L1/L2, respectively.
3. Simply move the marker to anywhere in the game world you would like Cole to move.
4. Press [X] and exit the editor (don't save); Cole will now be at the location of the editor marker.

This is very useful if you happen to not feel like walking from one end of the city to the other. This can also be used to obtain the "Back to the Bayou" trophy as soon as the UGC becomes available to you in the game.

Repeatable 100 XP
After you use the transfer device in the story mission Storm the Fort, you'll get a bonus for 100 XP. If you kill yourself using the deep water to your left, you'll respawn at the same point and get the 100 XP. You can repeat this as many times as you like.