Richard Branson’s Virgin Atlantic airline has what are probably the most restrictive carryon rules of any carrier flying out of the US:
Passengers departing from US airports are permitted to carry one item of cabin baggage each. Cabin baggage must not exceed a maximum length of 56 cm, width of 36 cm and depth of 23 cm including wheels, handles, side pockets etc. Other bags, such as handbags, may be carried within the single item of cabin baggage. All items will be x-ray screened and must not exceed 6 kilos in weight in Economy and Premium Economy, and 8 kilos in Upper Class. — from virgin-atlantic.com
This essentially the BAA rule (everything in one bag) plus the ridiculous 6kg (that’s 13.2 pounds) restriction. It’s certainly possible to travel with under 13 pounds in one bag — I do — but it’s going to be a real pain for most of us. At least the fares are cheap. I’ll bet Richard Branson’s hair weight more than 6kg.