TNT is deciding about the Season six, and this is their official survey:
Every vote may be important, so go and do it - it's funny and very well done.
Btw, if you finish it completely, and become their member, you may vote for Leverage on their pages. They also have forums.
WARNING: Lie about your age - TNT values grown ups more, so state you're 30-50.
If you're not from USA, you won't be able to become meber, so...lie :D
Remember, it's important to give them what they want to hear, and not what you really think :D
Also, try to do it as soon as possible, because they're probably waiting for ratings of last night episodes, and we don't have much time.