I'm always looking for the lightest weight totes that you can use for so many things when you're away from laptop bags to gym bags.
These bags are so easy to carry, to pack away if you want to and or to hook over the handles of your wheelie when you're heading for the plane.
I particularly love - other than Prada's metallic nylon tote - Ted Baker's navy and black nylon tote with leather handles which would do perfectly from travel to town and Liphault's City Plume Duffle which along with being as light as a feather has a sewn in strap on the back so you can hook it over your wheelie - I have one and wouldn't go anywhere without it.
Longchamp's Le Pliage Tote is one of the best because you can take it in one of your other totes all folded into its little pocket for when shopping gets the better of you. It'll take you to the gym, out for the day and carry it with you all the time.....just in case.
It's great to have a collection of bags to change as and when the mood takes you, but when you're on the move, travelling, nothing works as well as a double duty lightweight tote.