Attention span of a what?

One of today's comments from our Squeen of Silly (Carla Sonheim) is about attention span... her example:  What do you have the attention span of?

A:  I am just like the Squeen. I have the attention span of a pea.

I think I have the attention span of a zucchini… it can be really short and tiny or it can be like that large long overgrown thing found hiding under the leaves. heehee!

What do YOU have the attention span of?