It appears that I am too late! Someone named Davidissimo has gone back in time four years and coined my new word right out from under me!
As I try to figure out how he was able to construct a time machine able to read my thoughts and then travel back to the year 2003 and post them on the Internet, I will go ahead and post the word here, anyway.
(Actually, I was already aware that this word has been around for a while, I can't really remember when I first started saying it, probably somewhere around 2003 or 2004 when I was a senior in college. So I take no credit for its invention, but I love it nonetheless.)
usage: adjective or interjection.
Slang or abbreviation for "sweet". As Davidissimo points out, it can be used by itself or in conjunction with the word sweet.
Dude #1: "Hey did you see that Sony is thinking about cutting the price of the PS3?"
Dude #2: "Oh, that would be swiggity sweet!"
Dude #1 (upon finding a 5 dollar bill in the couch cushions): "Swiggity."