About 'needing' to have at least 3 carryons, can't you consolidate some of the items into 2 bags? I too sometimes travel alone, and when I do I bring my laptop. I bought a 3-pocket Timberland backpack in 1997 (average sized backpack that I used in college to carry books) that has a compartment designated for laptops. I put my laptop in that part (which is in the main pocket), then also use that large pocket to store any essential clothing I need and some bottled water. In the other 2 pockets I store my travel itinerary, essential toiletries (toothbrush, hairbrush, etc.), and some snacks. Then I bring a small travel purse (either a small regular purse, or when going to WDW a minibackpack the size of a small purse) where I keep my wallet, cell phone, ID, etc. I can usually squeeze this travel purse into the large pocket of the backpack, reducing my carryons to just the one backpack. Sometimes on the way home I will have a souvenir I dont' want to check so the travel purse will not always fit comfotably on the way home. This eliminates the need to have a separate carryon for clothing, a laptop, and a purse. It also makes it much easier to travel through airports knowing I just have the one bag (possibly 2) to carry.
