First, create SharePoint project just like in this article that will have the following in Elements.xml (check this link: http://www.sharemuch.com/2010/01/20/creating-site-level-ribbon-tabs-in-sharepoint-2010-hiding-ribbon-on-demand/)

Basically a tab definition on a main Ribbon. NEXT, you have to create either a delegate control or a user control in your masterpage that will be called every the time the page loads and execute the following: Microsoft.SharePoint.WebControls.SPRibbon.GetCurrent(this.Page).MakeTabAvailable(“MyProject.Ribbon.HelloTab”);

You can use this to verify if the tab was already enabled:
Microsoft.SharePoint.WebControls.SPRibbon.GetCurrent(this.Page).IsTabAvailable(“MyProject.Ribbon.HelloTab”)

Hope that helps!

Thanks for the quick reply! I haven’t figured it out yet, but I did stumble across a bit of additional info from Elisabeth Olson @ MSFT within this forum entry:

http://social.technet.microsoft.com/Forums/en/sharepoint2010customization/thread/d548d166-1afe-43c9-9562-0d6c1a771e1f?prof=required&wa=wsignin1.0

Unfortunately, adding a CommandUIHandler and executing the SPRibbon.MakeTabAvailable method within the user control’s OnPreRender method didn’t do the trick for me (i.e., the user control that’s added to the default.master “AdditionalPageHead” delegate control).

Thanks again,

Ash

It looks like in order to have the custom tab show up on the page, one needs to add a web part that will enable it. Not as seemless as I was hoping..