Various models of new physics predict the existence of particles with lifetimes of order picoseconds to nanoseconds, a range ideally suited for discovery in modern particle detectors. Candidate particles range from GeV-scale Higgs scalars and inflatons to supersymmetric particles at the TeV scale. I will describe two recent, first-of-their-kind searches for long-lived particles. The first is a search for high-mass neutralinos and gluinos in 8 TeV proton-proton collisions collected by the ATLAS detector. The second is an inclusive search performed in ~10 GeV electron-positron collisions collected by the BABAR detector. The implications for physics beyond the SM will be discussed, as will the outlook for subsequent measurements.