I have owned 2 previous day packs and I think this one is a good size and solid construction for a day trip.  It has padding in the back for comfort and laptop/iPod cushioning, but no interior pockets or slots in which to slip one of these devices, nor for small electronics like an MP3 or cell phone.  Instead, I used a couple of ziplock bags as interior "pockets" for small items.  Side slots were sturdy and held a large water bottle, large glasses case, umbrella, etc.  Exterior front zipper pocket was large enough for a couple of zipper bags, cell phone, small notepad, document case, etc. The straps unhook at the bottom to allow you to attach the pack to a luggage rack on a train.  When we were forced to check the pack at museums or train stations, we put the valuables we couldn't carry in this day pack, and attached a luggage lock, in hopes no one would have the energy to bother with it.  I did feel like the several security features added a bit more peace of mind than an average backpack, but no pack will discourage a determined pickpocket for long, so remain on your guard. Also, due to the cushioning on the back, you will NOT be able to fold this pack under your arm like a purse, (in order to avoid checking it at museums that require you do so).  However, my friend was carrying one you COULD fold, and the guards didn't seem to fall for that trick anyhow...