Thank you for writing.
You can access the RadRibbonBar's ApplicationButton and set the DisplayStyle and Text through the following code:
RadApplicationMenuButtonElement appButton =
appButton.DisplayStyle = DisplayStyle.Text;
I hope this will help you. If you have further questions, I would be glad to help.
the Telerik team
Q2’11 SP1 of RadControls for WinForms is available for download (see what's new); also available is the Q3'11 Roadmap for Telerik Windows Forms controls.