implementing per user home/url

[eluser]spherop[/eluser]
pretty new to ci and loving it so far.

i am working on a web app which involves users sharing videos. i would like to implement the kind of feature you see on a site such as flickr, where a url such as http://www.flickr.com/photos/userx/ will present a public view of userx's image stream. so each user, with unique username, automatically has their own simple url to share with others.

so, with ci, any tips on whether/how this can be implemented?