Imserba
At Imserba, which dubs itself the "Mobile Portal and Forum," there are free cheat codes for all types of video games, with many mobile phone games among them. The games are alphabetized in a list from A to Z, with 13 to 14 pages of game titles per letter. Just have the exact, correct game title and look it up. Once you find it, click on the link for that title, and straightforward cheats will be given to you, with specific buttons to press or codes to type in at the correct time on your phone.
Cheatbot
Like Imserba, only with a larger database, Cheatbot allows you to search for mobile phone games amid the 59,000 games it has codes available for. While its search engine is based on platforms, it is important to search on the mobile/cell phone platform in the search engine, or if your specific cell phone is listed--like the Palm OS, Pocket PC or the Nokia N-Gage--you can do a more targeted search through those as well. Once the search comes back with results, simply click on the name of your game. However, most of the nearly 2,200 mobile phone games listed don't have cheat codes, though Cheatbot encourages you to check back regularly.
iPhone Cheat Sheet
At iPhone Cheat Sheet, a forum has been set up where gamers obsessed with the new iPhone technology and seriously addicting game apps can put the cheats that they have discovered in individual games. The iPhone games are on the forefront of gaming technology because the games are usually simple but incredibly fun, have decent to great graphics and don't rely on buttons on the phone to be pushed, only parts of the touch screen or the ability to turn the phone itself. As this technology is quite new, there aren't as many iPhone games and even fewer with real cheats. But this library will grow as the number of games and popularity of the iPhone continue to grow.