With Citi AA cards, the two browser trick is not necessary. 2 apps for me and 2 apps for my wife, all consecutive and all in one browser. The more appropriate title should be "two consecutive apps trick" but that doesn't have the same ring to it.

I understand though a few people have a cookie problem with submitting two cons. apps, hence the apply, clear cookies, and reapply in a different browser for good measure.