This can be done another way too. You must be on your WiFi and also have a PC connected to same network. Then what you do is download app from market called WiFi Keyboard and enter cheats via PC to your phone.
1) Download WiFi Keyboard from market
3) Go to Settings -> Locale and text
4) Tick WiFiKeyboard (press OK on attention message)
5) Touch Select input method
6) Select WiFiKeyboard
In your notification bar, you will notice an URL address. When you open notification bar and see this URL, go type it in your PC browser. Use Chrome or FireFox recommended.
7) Enter the URL from notification bar into your PC browser
8) WiFi Keyboard page opens
9) Run the game on your phone
10) When in game, type cheats in input window on your PC (maybe press enter after done)
11) Watch "cheat activated" on your phone, done!
*note: you can also use wifi keyboard for example to type other text in your phone, like sms, email, etc..
**note: to set back your input method, go to settings -> locale and text, then select your desired input method.
Hope this helps, enjoy cheating :P