I've never managed to weigh mine but it's definitely a lot lighter as a fixie than with the sram 7 hub. Things I did to help the diet:

1) Ground off the kickstand
2) Ground off the pump fixings on the seat tube
3) Ground off the chainguard angle bracket
(all with a dremel. Took a bit too long)

4) Fitted carbon seatpost and lightweight saddle
5) Lightweight alloy bars and stem; originally I had an adjustable Kalloy stem but this weighed a ton.
6) Took off rear brake, mudguards (Summer) and rack

Sadly the susp forks added to the weight. I'd love something better but carbon bmx ones are supposedly pretty fragile and I like having a bit of bounce up front.

Folding Stelvio tyres save a bit of weight too, as would some carbon cranks and eggbeater pedals...

But as they say - no matter how fast you make a pig go- it's still only a fast pig and not a greyhound...