The Nitrogen-Vacancy (NV) center in diamond — a spin-1 point defect formed by a substitutional nitrogen adjacent to a vacancy site — is presently the focus of intense research in areas spanning physics, chemistry, and biology. Thanks to their long spin coherence times at room temperature, NV centers within diamond nanostructures are being explored as a platform for various technologies, most notably nanoscale resolution MRI and spin-based quantum information processing. In this talk, I will discuss recent experiments on the use of NV centers for nanoscale spin sensing. In particular, I will present results on the use of near-surface NVs to detect proton spins from an organic film deposited on the diamond crystal surface (the effective sample volume being approximately (5 nm)3). I will also touch upon a technique allowing us to obtain an NV-detected proton ‘free-induction-decay’ without the need for nuclear spin pre-polarization. If time allows, I will discuss recent experiments with diamond nanocrystals, where we use the NV as a probe to expose other, optically-inactive paramagnetic centers within the particle and on its surface.