Yea, caching that page sounds like a great idea, depending on how you do it, of course.

The cron idea is great in most circumstances, but in low-traffic sites, the cron could produce more hits than.. visitors.

One thing to think about when timing the cron is: "Will there be a visitor at least every [time * 2] minutes?"

The other alternative to crons would be to make a self check:

(pseudo code)