Pro Fit is an excellent general purpose scientific data analysis & plotting software for the Mac. Its best feature is a powerful built-in Pascal-style script language, which compiles natively (rather than interpreted) and runs pretty fast.
Image Acquisition (on the Mac)
The Imaging Source sells inexpensive Firewire/IIDC-compliant c-mount CCD cameras with resolution up to 1280×960 pixels; options include digita I/O and external triggering via TTL. Cameras come with a decent end-user image capture program (Windows only) and LabView drivers.
Astro IIDC is an excellent image capture software for the Mac. It works with IIDC compliant Firewire cameras, such as ones from The Imaging Source. Astro IIDC captures uncompressed video at up to 60 fps, and offers full camera control (exposure, gamma, gain, triggering, &c). Other features include time-stamping, field flattening, dark-frame subtraction, &c.
With an appropriate Firewire camera, Astro IIDC, a TTL trigger/delay circuit (such as the 1606-2-ST by the Kapture Group), one can build a fairly cheap & versatile digital image acquisition system for video microscopy, particle tracking, machine vision, &c.
Image Analysis