This is just one HTML page. The starting point.
load 'me' links. Now we've got 5-10 or so links. Load those pages.
The twitter me page is going to have 40 or so friend links. Load those pages.
Each friend has on average 3 me pages. Thats 120 links. Load those pages.
On each friend's me page, look for the link tag that signifies the RSS URL for this page, assuming the URL is not already an RSS feed.
From one starting URL, we have a collection of RSS feeds to pull in. All this feed reading will be going on in the background.
Define filters and various display settings. A straight timeline of all feed entries. All entries for a specific user, or a specific service.
The result is a high-quality activity stream to display in the application.