Recent trip overseas to Hong Kong.. had a Patagonia Maximum Cabin Luggage (wheelie back pack)
http://www.patagonia.com/web/eu/product/product_focus.jsp?OPTION=PRODUCT_FOCUS_DISPLAY_HAN DLER&catcode=MAIN_FA_EU.CLOTHING_GEAR.PACKS/TRAVEL_GEAR.WHEELED/DUFFEL_BAGS&style_color=49111-689&ws=
... as carry on.. with Netbook sized 'brief case' as well...
Week long stay.
Not problem with either in the cabin (steerage in A340 and B747).