Do tourist beacon messages get re-sent?

[BradHann]

So let's say - purely hypothetically, of course *ahem* - that I scan a tourist beacon, read the message, think "oh that's neat" and then delete the message. And then suppose I come back to the same beacon some time later and scan it again. This time I don't get the message. So... is there any way that I can retrieve the message? Will it time out eventually and I can rescan the beacon after a certain amount of time has lapsed?