I've got a Skip Hop bag. Bought it a couple of weeks ago from the Baby Show at the NEC. I think HappyBags is the stockist - so if you google on the name you should get a link.
I've got a brown cord one that doesn't smack CHANGING BAG so it can be used later. It cost £55 which some may think is pricey but I think is worth the money. I previously had a Bambino Mio rucksack which was just too big on a daily basis.
The bag does come with a shoulder strap but can be clipped onto the pushchair. I have a Jane Powertrack and it fits on fine. HTH
kipling baby bags do theyre fairly expensive but really good quality and mashine washable(time after time )
kipling baby bags
mine is the supernanny one dont know if the others had straps you could ring and ask-they're very helpful and they dont charge p&p
hotmama1 - do you have rough dimensions of the skip hop bag ? I quite like the look of them. I currently have a shanghai bag which is quite big and not wearing too well so looking for another but the website doesn't have dimensions on......