Feeds: solution with most frequent/real time/push notification update of feeds (e.g. for twitter tweets)? Which module (or solution) provides the quickest update of feeds after their source is updated? E.g. with Twitter if a new tweet is posted, which Drupal feed or twitter solution updates the quickest following that tweet? (I'd also be looking for general feed solutions for youtube etc).

I currently use feed aggregator which has minimum refresh interval of 15 minutes.

Do solutions require/work better if linked to a cron task?

Are there any real time genuine (i.e. not pseudo*) push notification solutions out there? Please give examples for particular feeds (e.g. twitter, youtube etc.) *by pseudo I mean a high frequency polling solution that appears to be near real time but is actually a pull on the feed from the drupal site rather than a push from the feed source.

Can feed sources like twitter be configured to know about subscribed external sites such that they can push updates to them?

By the way, currently evaluating the following as part of a solution for e.g. twitter (any specific advice on these welcome as is general advice on other solutions including for other feed sources such as youtube).


http://drupal.org/project/twitter 
http://drupal.org/project/oauth
http://drupal.org/project/twitter_pull
It looks like Twitter's "Streaming API" is your solution. However, I would look closely at their Pre-Launch Checklist before going down that route. They have 10+ things that you should comply with before becoming a stream or push consumer of their API.

Maybe a solution that would fit you is to develop a twitter stream client (that would be your server), and then to have your application users connect to your server via node.js, since node.js provides a "persistent" connection suitable for chat rooms and push-like notifications.

This is an interesting (and probably doable) suggestion, but not something that you would find pre-packaged in a Drupal module.