Automatic invitations

When inviting friends you're only able to invite 1 person at a time.
However, when checking other online-communities like http://www.hi5.com there's a huge difference:

they seem to have to posibility to retrieve all contacts from MSN and automaticly sending invitations. On top of that, if someone is already invited by someone else they are automaticly added to the buddy-list.

This would be a very nice feature i think ...