This may be the most useful thing WotC has published on its website to date. It will probably get very little use by most groups, because the word on the street is that people just don't use ritual spells these days. It is a complete compilation of all rituals published to date by WotC in its various books, modules, and interweb magazines. It sorts them by type and also lists them by different uses at the end.
Apparently, rituals are a very underused resource in typical 4e D&D games. This is probably because, the Rules As Written demand you give up some of your hard-earned gold for a one-time (possible) benefit. Player understanding of rituals is also a big time-sink. The players have a lot to think about at the table already, keeping track of powers and feats and status ailments and such. Getting the hang of the ritual system requires a LOT of reading and perusing texts and asking questions, when they've already done a whole lot of that. Nevermind the fact that the rituals are spread out over some twenty different sources. They are all easily accessible via the online Compendium, but that's still a whole lot of reading and processing to do.
So, how am I planning to get my players more invested in ritual use? Well thank you for asking.
First, screw paying for them. I treat ritual components like ammo and encumberance: we're not keeping track of it.
Second, start including ritual scrolls in treasure parcels. Well, actually, I don't worry a whole lot about parcels and such. We don't don't worry about experience points either. Everyone levels up when I say they do. If we tried to follow the Rules as Written, it would take forever to advance out of the Heroic tier. I mean, really, the campaign world is all about floating islands in the freakin sky, so I think verisimilitude isn't all that terribly important. It's more about creating an epic story and having fun. Where was I? Oh yeah. Give the players ritual scrolls. Can't hurt. They'll either use them or lose them in the bag of holding.
Yeah, this game is run fast and loose. Story, combat, role-playing, all good. It's not Dark Sun. The world won't kill the players if they don't have enough water. It's an epic tale. You never see Luke Skywalker worried about where his next meal might come from, after all.