Let me start off by saying that I have a bag fetish. I live for bags and love all the different options for carrying around my MacBook in style. Whether it's a shoulder bag, messenger bag or backpack, each has its application and place. A bag is a part of your wardrobe and should be treated as such.
Nothing is worse than seeing a sharply dressed business man or woman schlepping an ugly-ass computer bag (usually in black) that SCREAMS "there's an equally ugly computer in here!"
People that know me know that I gravitate to nylon bags and generally prefer messengers (my current faves are Crumpler, Timbuk2, Waterfield, Chrome, Tom Bihn, Brenthaven, STM). But there are also a bunch of bags in the nylon family that I have yet to try (Booq, Incase, Axio, Marware, Spire, Tucano and Oakley to name a few.)
There are tons of options for hipsters and students that favor bags in cool colors on nylon, but what about business users? As I find my self getting a little older and having to meet with more conservative clients and professionals, I find that there's times when it's not really appropriate to drag along a sunburst messenger bag.
I have traditionally avoided the stereotypical "business" computer bags (Tumi, Samsonite, etc.) because they tend to look a little too generic. Instead I prefer conservative bags from traditional designers like Kenneth Cole and Cole Haan. There's also a really sweet leather bag from a company called Ghurka, but I can't exactly justify US$1,600 for their Garrison bag thank you very much.
So, my question to you, fair reader, is which bag do you use for your PowerBook or MacBook and why? Bonus points for sexy looking business leather.