Cross-realm RealID raiding
has taken World of Warcraft by storm
ever since the ability to enter old raids with RealID friends was introduced in patch 4.3.2. Fearing the end of server communities and the collapse of civilization, players were instead greeted with a quickly mobilizing mass of players on Twitter, Reddit, and other social media to form cross-server communities for raiding. Without server boundaries, these groups can recruit from a larger pool and have more time flexibility. BattleTags
will make this all easier.
Over the last few weeks, many cross-realm raiding websites and resources have popped up. If you're looking to get into a cross-realm raid, here's a handy list of many places out there that are putting together old raids without the hindrance of those pesky servers.