As for the first question, it's trickier than it should be (IMO). I have also been trying to work out a way around it. Sadly I suspect it falls outside the realm of "novice tutorials."
Google implemented a push notification system based on XMPP specifically for their GTalk stuff, Originally they planned to open this to every app developer to allow them to use push notifications in other software (you may have seen some youtube videos with talk to this effect), however they apparently ran into some security and management problems with this approach (to do with tying the XMPP credentials into a Google / Gmail account), so they removed it.
If you search around the web for XMPP (Jabber) and android you may be able to find some useful information on the topic. The best looking sample I have found is here http://davanum.wordpress.com/2007/12/31 ... -for-xmpp/
(note the newer code sample linked at the top of the page.) I think it uses a JAR library for Smack (which I'm given to understand is the underlying code that the GTalk stuff uses anyway.)
I haven't tried to get this working yet as I'm trying to get my head around the underlying technologies, so I can't warrant that the code is any use.
The other approach is to use a long-polling pull technique such as COMET. This would usually be superior to timed polling, as it gives an "instant" update when the server state changes. http://en.wikipedia.org/wiki/Comet_(programming
.) Again, searching the web may provide useful examples.
Sorry I couldn't be more help, but hopefully that will give you something to base your research on.