Temperature control

[Aquattro]

So, summer is here (ok, not so much) and this is the time of year people drop in looking for ideas on temp control. What is everyone doing, or planning on doing in mid July when the days hit 30?
chillers, frozen pop bottles in the sump, alternate lighting schedules, etc?

Let's hear all the great ideas, and any experiences on past "great ideas", thoughts on what is acceptable, what is not for temp swings.

Go on, heat it up!