I have mentioned a few times about OpenRaid. It is a project that was started to use the RealID idea to its fullest potential. Once you are registered on the website, you can opt to share your real ID email. Like most factions in WoW, you start at neutral reputation with the website (faction). Then you can browse through the monstrous log of raids that players like yourself put up on a daily basis. The only think you cannot do with RealID people is Dragon Soul on Normal or Heroic (LFR is still game… though why would you want to).
There are literally raids for everything. People are raiding Vanilla and TBC content (I know it is solo-able but more fun with a few people). I myself will wrap up all of my Wrath of the Lich king achievements in the 25-player version later tonight by killing the Lich King on heroic mode. There are a ton of raids for Cataclysm content with groups attempting heroic modes, achievements and transmorg farming runs for tier 12 and below. The site also has a comprehensive search system so you can find your own raids. There are even PvP premade groups. I ran Battle for Gilneas and got the perfection achievement (2000-0 score) just last night. You can even form up your own raid for people to sign-up for from day one.
Once you are registered and have shared your RealID details, you can sign-up for the raid and detail your availability (maybe coming or coming), and the raidleaders can then choose which people to take with the. They can even designate assists to allow trusted people to help them manage said raid. They even provide a massive Ventrilo server for free for people who want to coordinate better via voice chat.
I can go on and on about the site’s features and usefulness, but suffice it to say, OpenRaid allows you to raid all content just below the current tier, even if your guild does not, and even if you are not part of a large organized guild. It is an invaluable tool, one that already has over 20,000+ users, and you should get on board while you can!