I've posted a question to superuser.com on Google Spreadsheets that I would like to move to webapps.stackexchange.com.
I think adding a function for moving the question to another Stack Exchange site (for the user who wrote the question) could be useful.
As @Michael said, a user with 250 reputation could ask other users to vote to move his own question to another Stack Exchange site, so why not just let the user move his own question?
Since users with 3000 reputation can move any question to any Stack Exchange site, experienced users can fix any inappropriate moves by inexperienced users, avoiding the delay of a vote.