How do I get the username of the currently displayed profile in a SharePoint Webpart for MySites

I am writing a web par开发者_运维问答t that will be displayed in public SharePoint My Sites. This part will display some 3rd party information for the user whose profile is being displayed. For example, if UserA is viewing UserB's profile, then it will show some information about UserB. How do I go about getting the username 'UserB' in the webpart code? Is it safe to use the 'accountName' query string param, or is there another, better way to do this from the SP object model?