In [Outlook/Notes], I could add [voting/radio] buttons to a message and track the replies from recipients. Can I do the same thing in Gmail?
Yes, the combination of Gmail and Google Docs provides a similar feature, but with even more options. At the top of your Mail window, click Docs. Then click New > Form. Use the options on the form to create voting options (or many other types of questions and fields), and then email the form. To track results, simply return to the form and click See responses. For details about using forms, see the Google Help Center.