As you Kindle owners have discovered, Amazon has you trapped as to what apps you can install. Also, what's available is far below what is available through the Android Market. I struggled with this for awhile but found a solution. Here's what you need:
An Android phone and a mini USB cord. These usually come with an Android and double as the power cord. Download and install the
Astro File Manager app on your Android.
Start the app and select "Application Backup". You will be presented with all the apps installed on your Android. Select the ones you want to backup (transfer to the Kindle), then select Backup. Those apps will then be stored separately as single files with an extension of xxxx.apk As an example the IRV2 app will be named: iRV2 Forum-56.apk
Now plug your mini USB cable into your Android and your desktop or laptop. Make sure you select "Disk Drive" as a connection type. Now go to Windows Explorer and locate the APK files on the Android. Then just copy or move them to your disk drive.
Second step. On the Kindle, go to Settings>Devices and set “Allow Installation of Applications” to ON. If not already installed, install the Easy Installer app from Amazon on to the Kindle. Plug the mini USB into the Kindle and your computer (the same cord from the phone will work). The screen will say "You can now transfer files to your Kindle". Now open Windows Explorer and copy or move the apk files to the root of the Kindle drive.
Unplug the cord and start the Easy Installer. The apps you copied to the Kindle will be listed. Simply check each file you want to install and select "Install Selected Apps". You are done.
Note: Since the Kindle isn't GPS capable, it will not run apps such as, Gas Buddy, AllStays, Passport America, etc. I tried Gas Buddy and the Kindle doesn't even see the file. Apparently it knows which apps it can install. BTW, the IRV2 app works like a champ on the Kindle.

Enjoy!
John...