Same method as me, Chairman Bill.
I have a CCS Snowflake bag and it will hold my 350D and 18-55 lens. I use it for ski touring mainly. Otherwise I use a CCS case whose name I can't remember with a snap buckle lid and a front pocket, which is useful for spare memory cards, filters and batteries.
Chris, the CCS pouch you refer to is the Kangaroo (smaller version is the Wallaby).
I use a variety of CCS pouches (Warthog, med & large/Kangaroo/Snowflake) and have done since my film cameras (Olympus OM) My current cameras (Olympus E-1 & E-3) still actually fit the same pouches as the OM's. I either carry them attached to the rucksack shoulder straps or on the/a waist belt.
If photography is secondary to hiking etc I generally only carry 1 lens, an 11-22mm (22-44mm in 35mm film terms) or a 14-54mm (28-108) I may on ocassion add an old Olympus OM fit 50mm f/1.8 + adapter (for shallow DOF effects) or a 1.4 teleconvertor.
If my main purpose is photography I use Dakine Sequence backpack to carry 1x Body, the above lenses plus a 50-200mm (100-400mm), Cokin P filter holder, 3 x Cokin ND, 3 x Cokin ND Grad, 1 x Polarising Filter plus batteries and other odds and ends and A Velbon Sherpa Pro CF 631 EL fitted with a Giottos MH1001 QD Ball-Head.