i love my ergo!!
i use it more than my pram. i could seriously live without a pram and just have the ergo instead.
willow- i just put ds in the front position and then carry the nappy bag over my shoulder. seems to work fine. obviously it's better if you can do it without the bag- so when i'm in supermarket etc. i just leave the bag in the car and put my wallet in the front pocket.