Without stand: 2.3 kg (5.1 lbs). See above for the super lightweight LEGO stand I use.
I got it off eBay and it was a best offer on a used one and it was still $375.00 -- way, way too much for just a simple monitor but I couldn't resist

the price is the biggest problem.
I have a nine day code sprint / conference coming up in May. I will be away for six weeks July-August of which two will be spent at such things... I need a monitor in my backpack
Edit: I've gotten a Duragadget Laptop Sleeve For Acer Aspire Ethos 18.4" and it's a bit too wide but doesn't matter much, it's not much protection but it will protect the thing from scratches.