AE Scripts has a new uber script for After Effects.
The Expression Toolbox, by Chris Roe, "was created to help take the pain out of using and locating expressions. At some point you’ve probably come across an expression that you find yourself using on every other project you work on. The question is where do you store this expression? I noticed that a lot of people were storing their expressions in text files, without documentation of how they were used or where it could be found. Without knowing who created the expression or how to use it, you’re left waiting on an answer from a mailing list or web forum on how to properly apply it.
The next step for the Expression Toolbox will be an online entry system that will allow you to enter your expressions to a global web driven database that anybody can access. You will then be able to download the most recent version of this database directly from the script."