[QUOTE 5151130, member: 259"]You see a fair few people in Antwerp riding bikes holding conversations on mobiles and umbrellas simultaneously and they seem to get on OK.[/QUOTE]
I'm not sure holding conversations on umbrellas can ever be OK.
[QUOTE 5151130, member: 259"]In most of the Netherlands nobody would bat an eyelid, and they'd probably have a heavy bag of shopping hanging off of one bar grip to boot. I've never managed to get the hang of doing that.[/QUOTE]
I've done it. Wide handlebars help, but you have to be very very very cautious turning else the swinging bag can do strange things to the steering and if you get it wrong, it can swing into the spokes and probably tear the bag open, dumping the shopping on the cycleway. If you're really unlucky, it'll stop the wheel and skid you. Panniers are better. Even rucksacks. Baskets are OK but heavy bags will exceed their weight limit and other odd things can happen then.