A hand-held apparatus comprising: a housing sized and shaped to be held or manipulated using one hand of a user; a probe guide configured to provide a path for guiding travel by a probe to be inserted into skin of a subject at a desired or specified probe insertion angle that is not perpendicular to the skin of the subject at a location at which the probe is to be inserted; an ultrasonic transducer located on or within the housing and configured to generate ultrasonic energy directed into tissue of the subject at the desired or specified probe insertion angle and configured to receive a portion of the ultrasonic energy reflected by a target located within the tissue, the ultrasonic transducer being angled to more effectively direct the ultrasonic energy at the desired or specified probe insertion angle; a processor circuit configured to control the ultrasonic transducer to generate or receive ultrasonic energy and configured to obtain information indicative of the ultrasonic energy reflected by the target; a motion tracking circuit configured to provide information indicative of a motion of at least a portion of the hand-held apparatus to the processor circuit ; and a display located on or within the housing and configured to present information about a location of the target with respect to a portion of the hand-held apparatus, the information about the location determined by the processor circuit using the obtained information indicative of the ultrasonic energy reflected by the target and the information indicative of the motion of the hand-held apparatus obtained from the motion tracking circuit . a housing sized and shaped to be held or manipulated using one hand of a user; a probe guide configured to provide a path for guiding travel by a probe to be inserted into skin of a subject at a desired or specified probe insertion angle that is not perpendicular to the skin of the subject at a location at which the probe is to be inserted; an ultrasonic transducer located on or within the housing and configured to generate ultrasonic energy directed into tissue of the subject at the desired or specified probe insertion angle and configured to receive a portion of the ultrasonic energy reflected by a target located within the tissue, the ultrasonic transducer being angled to more effectively direct the ultrasonic energy at the desired or specified probe insertion angle; a processor circuit configured to control the ultrasonic transducer to generate or receive ultrasonic energy and configured to obtain information indicative of the ultrasonic energy reflected by the target; a motion tracking circuit configured to provide information indicative of a motion of at least a portion of the hand-held apparatus to the processor circuit ; and a display located on or within the housing and configured to present information about a location of the target with respect to a portion of the hand-held apparatus, the information about the location determined by the processor circuit using the obtained information indicative of the ultrasonic energy reflected by the target and the information indicative of the motion of the hand-held apparatus obtained from the motion tracking circuit . <EOS>