RSS feeds

[Tabo]

Im about 80% sure that this would be done using php.

How can I include an external feed to my own rss feed, for example my feed is at:

www.example.com/rss.xml

and I want that feed to aslo include news from

www.somthing.com/anotherfeed.xml


How can I do this, and keep it shown in chronological order??

thanks