Simply, well not super easy but still easy, install a fan on the inside of the unit.

ENGADGET: Your DIRECTV H20 running hot? Install a fan HD

There's a second alternative: A growing number of New Yorkers are going for duct-free AC systems that involve a small, wall-mounted indoor fan powered by a separate outdoor unit the size of suitcase.

WSJ: Ugliness for All

The MicroNet is fast, but installing the bulky unit was a chore, and its cooling fan is noisy.

CNN: IDG.net - Recordable and rewritable CD drives: Permanent, portable storage