Springing from such great minds as Richard Feynman, Eric Drexler and Richard Smalley, nanotechnology has become a hot item in science and engineering. Nanotechnology is advertised as offering the promise of the creation of useful, functional materials, devices, and systems through controlling and manipulating matter on the multi-nanometer-length scale, and exploiting novel phenomena and properties (physical, mechanical, electrical, chemical, biological) at that length scale. We will discuss some of the interesting scientific challenges that need to be addressed before nanotech can achieve its goals. The physical properties of materials do not scale neatly to the nanoscale, so there is a lot of new materials science to be learned. On the nanoscale things happen at a furious pace and dynamics are as import as structure. Therefore, we will need to develop a new class of ultrafast measuring probes.