I can recommend two places in Florence. The first is a very, very upscale kitchen supply store, with loads of beautiful cookware and other accessories.

Dino Bartonlini Via dei Servi, 30 r. tel. (055) 211895

The second is just a small hardware and kitchen supply store where you are probably more likely to find the pasta measuring stick. I actually like this store better than Bartolini for poking around in, and for picking up inexpensive gadgets.

Braschi Ferramenta e Utensileria Via del Corso, 67 r. (055) 287743

They are both more or less in the city center. Dino Bartolini is just a little northeast of the Duomo. It is on a corner of Via del Servi and one of the main streets heading towards the San Lorenzo Market (maybe Via M. Bufalini?). The Ferramenta is just off one of the pedestrian-only streets that head down from the Duomo towards the Ponte Vecchio. I think the Via del Corso runs due east off the Piazza della Repubblica.

Have fun, Joel