I have the Kata R-103 GDC Backpack that holds my Nikon D2X, 2 lenses, light meter, spare batteries, flash, filters and other stuff. It also has a laptop carpartment. Plus it comes with the TST tripod attachment that is very well ergo designed.
Check it out at: http://www.kata-bags.com/Item.asp?pid=275&...Id=4&ProdLine=4
Kata is a neat brand as all their bags are modular in design. I also have the W-92 waist pack for easy access to 'stuff' I need more than others without putting my back pack down.