[Update at 1:05 PM ET on 6/12/13: I was able to snag four San Fran passes the second the sale opened.

Despite the sale's very limited quantities, no cities have yet sold out.

End of update.]

Today is the third day of five weeks of discounted travel packages sponsored by the US Travel Association and American Express called Daily Getaways.

Every weekday at 1 PM ET, a discounted travel package or packages will go on sale and will sell out in a few minutes.