thanks for asking. You can use a custom menu to move the Application 
Manager to the root level of the menu. You can then:

1) Press Menu to enter the Remote Buddy Menu 
2) Keep the "Left" button pressed to go to the root level and select 
the Application Manger 
3) Then select the application

Or you go with your Command + Tab solution. I've just created an 
Action for what you want to do. You can download it here:

http://www.iospirit.com/static/objectfiles/file/90/ 
CommandTab.rbactionpack.zip

(Download, Unzip, Double-click, Map to a Button of your choice)

Best regards, 
Felix