1k+ blitz games played and still having a rating of 544 eludes me
would playing obscure openings throw grandmasters off guard

Not very likely but can happen once in a century I suppose.
Karpov lost once with white against Tony Miles when they opened 1 e4 a5 (or was it ...b5?). But Miles was a GM too, so he knew what he was doing.
Hi superking500--keep in mind that grandmasters aren't people who've memorized enough sequences of moves to win lucky games. They have profound understanding of development, tactics, and positional play, to the extent that they've defeated thousands of opponents from unknown situations. So they might think about the early moves more than if you played a book line, but they still aren't likely to uncork something horrendous in response.
you would continue watching them devolop and then destroy you for wasting moves on your turn. you would loose momentum and their structure would expose your weakness. play a 2500 rated computer with something like that and you will soon understand.

tigerprowl yoda is quite proud of hisself, or bluffing bigtime!? quite entertaining to read Estragon... i'm still figuring out the trunk lines myself, never wandering far from e4...c5 or d4...Nf6. kings gambit is fun to try on lower ranked oppenents ;)

I think if you start with a strange move like a4, a GM can convert the opening into a known opening.
you may still think you play your strange opening after move 5 but the GM may have transposed it into a pet opening.
a4 doesn't do anything on move 1 and the GM is free to play whatever he wants in the center.

tigerprowl yoda is quite proud of hisself, or bluffing bigtime!? quite entertaining to read Estragon... i'm still figuring out the trunk lines myself, never wandering far from e4...c5 or d4...Nf6. kings gambit is fun to try on lower ranked oppenents ;)
tigerprowl is being deadly serious, as indeed am I.

Not very likely but can happen once in a century I suppose.
Karpov lost once with white against Tony Miles when they opened 1 e4 a5 (or was it ...b5?). But Miles was a GM too, so he knew what he was doing.
It was 1. e4 a6!+, and is annotated on chessgames.com: http://www.chessgames.com/perl/chessgame?gid=1068157
Playing 1. a4 can be deadly against super-GMs. At least if it's the worlds blitz championsship, and your name is Magnus Carlsen: http://www.chessgames.com/perl/chessgame?gid=1671724

GMs have surely never heard of, much less seen, the move 1.b3
Good call.
you have obviously never heard of Grandmaster Bent Larsen.
http://www.chess.com/blog/kurtgodden/who-suggested-1-b3
he was known for playing b3 quite often.

GMs have surely never heard of, much less seen, the move 1.b3
Good call.
you have obviously never heard of Grandmaster Bent Larsen.
http://www.chess.com/blog/kurtgodden/who-suggested-1-b3
he was known for playing b3 quite often.
Not to mention 1. b3 is called the Larsen Attack (or Nimzo-Larsen or something like that)
GMs have surely never heard of, much less seen, the move 1.b3
Good call.
you have obviously never heard of Grandmaster Bent Larsen.
http://www.chess.com/blog/kurtgodden/who-suggested-1-b3
he was known for playing b3 quite often.
I guess sarcasm doesn't work well in text.
for example if you played say a4 or b4 against Magnus would he be thrown off guard by it?