Can anyone tell me how to add a Sharepoint "out-of-the-box" web part to an existing webpartpage's webpartzone from code (VS.net C#)?

I have developed an administrative web page (.net, c#) that creates an entire site collection structure based on many nested site (SPWeb) objects. I would like to add code to add various out-of-the-box web parts (eg: Announcements) to pre-defined webpartzones for certain SPWeb instances in my hierarchy. How can I do this? I don't want the site collection created from my script just to come up with empty web part pages and have to populate them all by hand...

Thanks for the help!