If Google isn’t open about something, it is often because they don’t want anyone gaming the system. Here’s the list of sources for RealTime Search, as reverse engineered by Search Engine Land
- Tweets from Twitter
- Google News links
- Google Blog Search links
- Brand new web pages
- Freshly updated web pages
- FriendFeed
- Jaiku
- Identi.ca
- TwitArmy
- Google Buzz
- MySpace updates
- Facebook fan page updates
- Quora
- Gowolla
- Plixi
- Me2day
- Twitgoo
It would be easy to update a few of these every time your site has new content – can’t harm, might help