You can just update a div in an ajaxy way, you don't need an iframe.
There are definitely some things I don't like about this approach, though, namely SEO/SEM considerations - content on the fly invites poor indexing of content (i.e., no content) if you're using an onload to pull the first n items, spiders won't see what you have to say.
There are definitely some things I don't like about this approach, though, namely SEO/SEM considerations - content on the fly invites poor indexing of content (i.e., no content) if you're using an onload to pull the first n items, spiders won't see what you have to say.