I'm going on a two week trip to Europe next month and I'm looking for a new pack. I currently have two LowPro bags that I use, Fastpack and Mini Trekker, but I'm getting tired of taking both with me.This trip we are going to sending a lot more time on the move and I'm ditching the SLR. To save time and hassle I'm looking to consolidate everything into one bag. My budget is less the $150 and if possible id like to keep to be able to carry on. So far I really like the "High Sierra 26" Railpass Travel Pack" http://www.amazon.com/High-Sierra-Railpass-Travel-Pack/dp/B000HZFRLU From the comments its seems like it will work for carry on if I remove the day pack. But I'm a little concerned that it might be a little small. Next on my list is the "High Sierra 29" Compass Travel Pack" http://www.amazon.com/High-Sierra-Compass-Travel-Pack/dp/B000HZC62I/ I know this one wont work for carry on but it's ~1,000 ci bigger and is only $10 more then the Railpass. Last on my list is the "Caribee Akula 65 Travel Backpack" http://www.amazon.com/Caribee-Akula-65-Travel-Backpack/dp/B005704VWQ Very big and has lost of options, but is at the very top end of my budget. Any info on any of these or other packs would be very helpful. Thanks.