I am sure that you have heard by now that the TSA will be allowing certain types of knives on flights within the USA. Before you get too excited, you should familiarize yourself with the rules because they are quite restrictive. I know there are knife makers working feverishly to bring new designs to market that are purpose built to meet the TSA’s regulations, but in the mean time, you may want to pick up something that already meets the criteria.
Blade HQ had the good idea of creating a section on their website that catalogs the knives that they carry that meet the TSA’s criteria for carry on. The pickings are somewhat slim right now but I expect that this list will grow once manufacturers can get geared up for new TSA worthy designs. Check out the TSA Approved Knives section at Blade HQ.