I've recently acquired more gear than will fit at a time in my current bag, and I'm looking for something that will fit what I've got to carry. Here's what I need to bring with a couple possible future items:

40d body (no grip)
50 1.8
macro tubes
sigma 10-20 w/hood
28-135 IS (no hood but maybe later)
70-200 f/2.8 sigma w/ hood
grad nd's/holders & a few filters
normal CF cards/release/cleaners/stuff

For the future, things I'd possibly be looking at:
-different probably slightly bigger lens for replacing the 28-135
-flash
-1.4 and 2.0 TC's
-another lens (probably something like the sigma 10mm FE)

I'm open to a DIY bag for the value, or a backpack type. I'd like something reasonably inconspicious though that doesn't scream "steal me!" My concern with the backpacks are the accessability of the stuff. If I'm on a backpacking trip the gear will probably just go in my regular pack and come out to shoot from there, but if I'm doing a day hike I want to be able to shoot reasonably quickly.

crumpler 6 or 7 million if you want "stock".
A few domke inserts (seems 2 2x1s and 1 center square would work) and any bag they'll fit in and a baseboard if you want DIY and stealth.

thieves are onto crumpler, do not...i repeat do not buy the 6 or 7 mil. homes, please. i know they're sick bags that are trendy with a gay little logo, but it's the filson, i promise.

you should look into making a DIY bag, it's super rewarding and you can EASILY make one to your exact liking for ~$60!

I think I want to go the DIY route. I just need to find something good to start off with now. I like my timbuk2 commuter bag but I don't want to give it up as a laptop/crap carrier bag.