Yep, it's annoying that most sites don't list bike weights. I guess most stock bikes are heavy and they would rather not advertise this fact unless it's a light bike. That said, some sites do list weight. I just bought a Kona King Kikapu, and under Kona's "download" section, the have an Excel spread on weights. They list mine as 29.8, but in reality it weighed just under 31 in the shop.
After I lost the reflectors and changed out the stem, seat and pedals, it's at 30 pounds.
FYI: I think Santa Cruz lists weights with various bike configurations.