ORCAE is an online genome annotation resource offering users the necessary tools and information to validate and correct gene annotations. The system is build on the wiki philosophy, all modifications to a certain gene are stored and can be found back in the annotation history of that gene. To be able to modify genes however you will need to have a user account. Anonymous users can browse the public genomes but don't have editing rights.
Sterck, L., Billiau, K., Abeel, T., Rouzé, P., Van de Peer, Y. (2012) ORCAE: online resource for community annotation of eukaryotes. Nat. Methods 9, 1041.