On Thursday May 26 from 16:00 - 19:00 Eastern Time (4:00 PM - 7:00 PM), Rockstar is hosting a Social Club Multiplayer Event. Please see my calendar blog post for a full Calendar of known events with a time zone converter and a description of the Social Club events.
These events generally include Triple XP for the duration of the session. Although the official event is being held for PS3 only, both platforms get Triple XP. The next event for XBL has not been posted yet, but will likely be in July (Thursday's event was originally planned for XBL, but the XBL event was moved up to May 5, swapping with the PSN event scheduled for that day that had to be cancelled due to the PSN outage).
2ks4 16:45, May 23, 2011 (UTC)