Many FOSS projects require Contributor License Agreements (CLA) for all contributors. Even though we have many common FOSS software licenses, it seems that these projects have to create their own CLAs.
Are there any standard/generic/reusable CLAs?
From Opensource FAQ:-
For more about contributor agreements in general, and some examples, see civiccommons.org/Contributor_Agreements. See also the Project Harmony, "...a community-centered group focused on contributor agreements for free and open source software (FOSS)."
At How to Accept Code and Documentation Contributions Legally you can find CLA examples
And of course the Linux http://developercertificate.org/ the simplest and best of all IMHO