Depending on your status, airlines & airports transiting and equipment (a/c) used for your booking, you need to figure out their rules on carryon - US carriers are flying smaller/regional jets on even medium to longer transcon. routes and enforcing the 1 carryon rules - typically on sizes and not (yet) on weights. MLC will be gate-checked as they won't fit in overhead bins on those CRJ's - underseat space is tight for larger "backpacks" ... We adapt and use different carry-on combo's to fit our itineraries - my backpack collection: STM for netbook/ipad, Eddie Bauer for notebook ... all the way up to eBags TLS Weekender Convertible that once tipped the airline counter's scale at 44.5 lbs loaded with gears (yup )

Can you travel with 1 laptop plus a tablet/e-reader plus in-ears NR headphone? Perhaps a multi-pocket travel vests to re-distribute & carry some of the gadgets, that "should" not be counted as you are wearing it to board ...

Too often, we've all seen folks stopped by GA and FA at the boarding ramp to be prompted to gate-check their "excess" bag, especially on a full/over-booked flight.