Looking for a quick and easy way to install a few APK files but don’t have a USB cable handy? Here’s a tip from a Lifehacker user: Put the files in your Dropbox account and you’re already halfway done. Open up the Dropbox app on your phone and click on the file. The rest is magic as the installer takes it from there. In an added bonus, you can share files with other Android users!  Don’t forget you’ll need to have your phone set up to permit non-Market sources to install apps.