re: COD 4: Double XP & 50% map pack

Yeah, Ziggy...if you play CoD4, and kill someone or capture a flag or a headquarters, you get the "+5" or "+10" or whatever when you do so. Those are your XP (or experience points). You tally them in order to advance in rank (from level 1 to 55). Once you've run through and completed Level 55's worth of points, you're done. Unless you wish to "prestige." That means you do it all over again, losing all your guns and challenges and whathaveyou. You can do this up to 10 more times. Every prestige gets you a little symbol by your name while you're running through that prestige level. If you notice, many people have the gold cross and a "55" next to their name. That just means they've completed every prestige level--all 10. I'm on my seventh right now.

PS, I think Double XP starts at 3:00.