Messaging/Notifications Advice please?

Hello folks,

Having very successfully wrecked my test site ;-) I decided to do a fresh install (AGAIN!!!) This time I thought I would read the OG readme properly (you know it makes sense!) OK, so the author recommends enabling Notifications/Messaging modules, ok did that. However http://drupal.org/project/messaging says that: Sending Methods must be set up, the choices:

* New Twitter: developed by Will White (Drupal 6 only, requires Twitter module)
* Instant Messaging: XMPP, using XMPP Framework (Drupal 6 only)
* SMS, developed by Tim Cullen (Requires SMS Framework)
* Plain text Mail: simple gateway using Drupal standard mail functions
* HTML mail: PHPMailer, contributed by Ted Serbinski
* Privatemsg, integrating with Privatemsg module (Drupal 5 only)
* Mime Mail, by Tim Cullen (Requires Mime Mail module, Drupal 6 upgrade in progress)

Eh, too many choices! How do I decide? What is the easiest one to use for testing purposes?

TYIA