A couple of years ago, I invested about $300 in a Lowepro backpacker camera bag. Unfortunately it doesn't allow for carrying a laptop in it. And I need my laptop to be in either my camera bag, or my second carry-on.

I'd like to hear what you use, and what you like. If I purchase a new backpack bag, I want it to be the maximum size that domestic airlines will allow (width + height + depth must equal 45" or less). I want my tripod to be centered on the back of the pack (not out on the side). If my laptop is right behind my tripod, I fear that the weight of the tripod and Really Right Stuff ball head will dent my laptop. Maybe they have done a good job designing their packs to avoid this.

Maybe I just need a new "second" bag. The problem is that a second carryon can't be larger than 15" x 11" x 6 (a combined total length of 32").

Or maybe I can find a hard "shell" for my 15" MacBookPro .... and then I can simply stuff it in one of my existing bags.