No matter what phone carrier service you have, the easiest way to install a Java program on your phone is through their online service. The reason? Not all phone models will run all Java programs-- usually true for models without a large display screen or models promoted as "no-frills." For certain jobs, ones with access to sensitive information, all personal cell phones must lack a camera, Internet service, etc.
The first step in the easy way of installing a Java program on your cell phone is to connect to the Internet. There should be some tab for Games or Applications in your cell phone's menu. Under this menu will be the option to get new programs.
In the early days of cell phone Internet applications, users could buy programs for a flat one-time fee. Now, cell phone companies have wised up and charge a monthly subscription fee for the program. For games, it is usually low (less than $5) for 30 days of access, and charged to your cell phone bill. If you don't renew, the application fails to work and you stop being charged.
Be wary of third-party games you get from text messaging a special code you see on late night TV, or from accessing the web with your phone outside of your carrier's main web area. It's not that these programs carry viruses or anything, thankfully yet, but they can become virus-like on your cell phone bill. It can be tough to get rid of them! When you purchase these games or services, a simple call to your cell phone carrier may not cancel the service. This can be difficult since you have to find a way to contact the third-party vendor you authorized to charge you for in the first place, and cancel through them.
A last way to install Java programs on your cell phone without incurring the data transfer fees is by connecting your cell phone to your computer. A cable with a regular USB end on one side and a mini USB on the other will work with most newer cell phone devices. For phones not compatible with mini-USB, stop by your device manufacturer's website to purchase a specialty cable just for connecting your cell phone model to a computer. However, most cell phone devices come with this cable in the original packaging, so check any stashes of miscellaneous cables you may have laying around the house.
Once the cell phone is connected to the computer, your computer should give a message of "Hey, I detected a new device." You can open the cell phone through My Computer, and then move the desired Java program from the location it is saved at on your computer to the cell phone. You may need to place it is a special folder to access it, and remember only Java programs written for a cell phone, and perhaps even your model specifically, are going to work.