[Suggestion] Charge 100 Influence to put a Wonder in any Queue, and include a message telling when a Wonder is now not available/available to build.
Even if you don't do anything else more extravagant with wonders, charging 100 Influence will prevent players just putting something in a queue to deny it to other players. It would also give more of a chance for the player to build Wonders on higher difficulties (providing the AI doesn't get heaps of bonus influence).