Crumpler Muffin Top 3000 Photo Bag - Black/Mustard I use this for quick access to a different lens. Handy and simple.
Lowepro Flipside 300 Photo Backpack for DSLR - Black Comfy to carry and plenty of space for other lenses.
Lowepro Flipside 400 AW Backpack for DSLR - Black Probably my next upgrade! Comfortable with room for extra stuff too.
Lowepro Fastpack 350 Quick Access Backpack for SLR Kit, 17" Notebook and General Gear - Black This is a Tardis! Great for travelling and doubling up as hand luggage.
Kata DR-461 Digital Rucksack For Small DSLR Systems Mini backpack - perfect for photo walks and taking on holiday.
Lowepro Topload Zoom Mini Case For SLR and Short Zoom for Canon 550D, 500D, 1000D, Nikon D3000, Samsung NX10, PL1, Panasonic G2, Sony Alpha A450 - Black Case Easy access and very small. Great when you don't want much to carry.
Billingham Hadley Pro Camera Bag (Khaki Canvas / Tan Leather) Fantastic looking bag for the sophisticated travelling snapper!