Mesoscale phenomena bridge the divide between atomic-level and bulk-level behavior and one of the most interesting and striking examples of mesoscale behavior is fast transport in carbon nanotube channels. Narrow hydrophobic inner pores of carbon nanotubes can be so small that they force water into a single hydrogen bonded chain, a conformation that does not exist in bulk state. Extreme degree of molecular confinement and smooth surfaces of these nanotube pores enable nearly frictionless flow of water, ions and small molecules through them, and even fast relaying of protons. We are studying the fundamentals of these fast transport phenomena using carbon nanotube porins — short carbon nanotubes that mimic the architecture and the functionality of biological membrane proteins. We are also incorporating carbon nanotube porins into artificial membranes and bioelectronic interfaces to take advantage of their unique structure and transport properties.