How can I get an .apk file to my phone? Possible Duplicate:
  How can I install an app given only its APK file?  




I just made a 'Hello World' app using Eclipse. Now I'd like to know how I can actually put the app onto my phone.
Must all apps be downloaded through the marketplace, or can I simply transfer it to my phone?
Right click on your project -> Android Tools -> Export Signed Application Package.

Export Android Application pops up.
Select your application press Next button,
Select Create new keystore radio button,
Give some location path and enter some passwords and press Next button.
Enter values into Alias, Password, Confirm Password, Validity and First and Last Name fileds. Press Next button.
Enter Destination APK Path. Press Finish button. 

Now your application apk file is ready to be installed on your phone. 
Use Bluetooth or USB cable transfer or any other way which you prefer to transfer the apk file to your mobile.

Use Explorer to locate your application and install the apk file.