I'm not sure of many places these days which aren't gay friendly, but if you're looking for a place with a very high gay guest ratio, I'd look at Provincetown, Mass and Rehoboth Beach, De. for starters.

There's also a more refined Ogunquit Maine and Northampton MA? If you're looking for a more blow the doors off the closet Gay Mardi Gras, then P'town is the place to be. They also have a few celebratory lesbian seasonal weekends that could be fun.

I'm sure you know this, but Key West!

A little more info would help.

IMHO Key West in August could be hellish. What weather are you looking for? And budget?

Provincetown

Provincetown. Northampton has no beach.

California, we really don't even notice.

Here are 20 suggestions: http://www.outtraveler.com/pictorials/story.asp?did=2069

HTtY

Fort Lauderdale; the water is warm enough to swim in without turning blue; there's a "gay beach" and there are plenty of nightlife venues which are both gay and gay friendly including good restaurants. Close enough to South Beach if that interests you; there aren't the "drag Duval in our redneck pickup" opportunities of Key West, however.

Let me add that Rehoboth is, as Neo mentioned, a great option; large "gay beach" and lots of decent restaurants; outlet and other shopping sans sales taxes. Only drawback might be accessibility since it is basically a place you need to drive to.

Fort Lauderdale in August? Save it for winter.

True, most big cities are very gay-friendly these days, so you'll have no problems there. But there may be some places of particular interest to women. This article might help you more than the other list: http://www.outtraveler.com/pictorials/story.asp?did=1504